Member Defections: Automatic By-elections

John Lamont Excerpts

Monday 16th March 2026 Westminster Hall

[Dr Savage]

The hon. Gentleman makes an excellent and valid point. My main job today, on behalf of the Petitions Committee, is to present both sides of the argument, but the point about data on voting intentions, which we work so hard to glean on doorsteps, is a key factor in the debate.

Others raise concerns that a requirement for a by-election could have unintended consequences, including potentially strengthening the power of party leaderships or discouraging MPs from following their conscience due to legitimate dissent. At this point, I want to clarify that when talking about defections, I am not talking about the case where an MP loses the Whip for reasons to do with the leadership, but about voluntary defections undertaken by an MP themselves. I do not think any of us would want a world where party Whips could threaten an MP with a mandatory by-election if we displease them in some way.

Public opinion on this question appears to be mixed, although polling suggests it is an issue on which many people hold strong views. Some surveys indicate that around 40% of respondents believe that it is unacceptable for an MP to defect, while others suggest that a majority of voters think a defection should trigger some sort of electoral test. Those numbers do not resolve the constitutional question, but they suggest that people far outside Westminster really care about this matter.

It is also worth putting the question into perspective. Party defections in this country are relatively rare, although they obviously sometimes occur in clusters during periods of political turbulence—possibly such as we are going through now. The last MPs to resign their seats and seek fresh mandate after defecting were Douglas Carswell and Mark Reckless in 2014, when they left the Conservative party to join UKIP. They refought their seats in by-elections.

[John Lamont (Berwickshire, Roxburgh and Selkirk) (Con)]

The hon. Lady is making the case well on behalf of the Petitions Committee. Over the years, there have been a number of examples of some of my former Conservative colleagues ending up alongside Lib Dems in the House of Commons. In those circumstances, is the hon. Lady of the view that there should have been a by-election for those MPs to get their mandates restated?

[Dr Savage]

I thank the hon. Gentleman for making that point. What we are talking about is the principle of the matter rather than specific defections from any one party to another.

This constitutional question has also been considered by Parliament previously. In 2011, a private Member’s Bill proposed that MPs who changed their party affiliation would have to face a by-election, and in 2020, another Bill proposed extending the Recall of MPs Act 2015 so that a voluntary change of party could trigger a recall petition. Neither progressed through Parliament, but the fact that the issue has arisen more than once suggests that it raises enduring questions about representation and accountability.

I would like to share some perspectives from other countries, because this is not a uniquely British debate, and other democracies have taken different approaches. Some, such as India, have adopted strict anti-defection laws under which MPs can lose their seat if they leave the party on whose ticket they were elected. Indian MPs are also, for the most part, compelled to vote with the Whip, which must make votes very, very boring. Others, such as New Zealand, have legislation designed to discourage what is sometimes referred to as “waka jumping”—I am reliably informed that that is effectively jumping from one canoe to another, which I can say from personal experience sounds like a very bad idea—although that approach has also prompted debate about the balance of power between MPs and party leadership. South Africa experimented with allowing MPs to cross the Floor, but later decided that that was a poor idea and prohibited it. That shows that views can change about how best to preserve electoral legitimacy.

The UK system has its own traditions and constitutional principles. Party affiliation plays an important role in how Governments are formed and how legislation passes, but MPs are also expected to exercise independent judgment. All of that means that there is no simple or obvious answer to the question raised by the petition of whether the current arrangements already strike the right balance between representation, independence and accountability, or whether there might be merit in exploring alternative mechanisms.

What is clear from the petition is that many members of the public care deeply about the relationship between voters and their representatives, how it works in practice and whether they feel that they are being represented in this place. I very much look forward to hearing the views of Members from across the House.

[Robbie Moore (Keighley and Ilkley) (Con)]

It is a pleasure to serve under your chairmanship, Sir Roger. I thank the hon. Member for South Cotswolds (Dr Savage) for introducing the debate on behalf of the Petitions Committee. It is unfortunate that although we have a 3-hour allocation to discuss this important topic, other Members of this House that have not felt it worthy of coming along to do so, despite having changed party in this parliamentary Session or in the previous one. It would have been interesting to have gained their views. I thank the over 129,000 individuals who signed the petition, illustrating that they care deeply and are passionate about a subject that is ultimately about trust.

I have been fortunate enough to represent Keighley and Ilkley for more than six years now, facing an election twice in that time in two very different political environments. In 2019, I was elected in a Conservative landslide, and more recently in 2024, I was elected during a time when national results were very much going the other way. Keighley and Ilkley is—or should be—a classic bellwether seat, and up until the last election, there had never been both a Labour Government nationally and a Conservative MP locally since the creation of the seat in 1885. In fact, ahead of the 2024 general election, 12 major polling companies predicted a Labour landslide in Keighley and Ilkley. Electoral Calculus gave me a 97% chance of losing my seat. I do not make these points merely to blow my own trumpet; the point I am making is that politics is ultimately about trust.

When we are elected by our constituents, they are putting their trust in us. They are trusting us not only to be a strong advocate for the area that we represent, but to stand by our manifesto pledges, both at a local level and those of the political party we represent. We stand by the values and commitments of the party we represent. The vast majority of us in this House are supported by volunteers who share our values, often hold party membership and support our policies, which have implications for all our constituencies.

Owing to the Representation of the People Act 1969, at every voting booth across the country our electors are greeted not only by our own names but by our party names and party logos. They put their cross in the box against a name and a party that they wish to represent them. A proportion of people out there will, of course, vote for the individual who they feel is most committed to representing them, but they are also casting their vote for a political party.

As has been demonstrated by all political parties, through the data that they collect, a proportion of the electorate cast their vote based on the national political party, rather than the individual who has been chosen to stand in that local area. It therefore comes down to the point that was made in the opening remarks from the hon. Member for South Cotswolds: this petition invites us to debate the difference between the individual and the party.

I do feel that when an individual is standing for a political party, if that individual then chooses to defect, cross the Floor of the House and join another political party, it is only right that a by-election is triggered. That would give the electorate the absolute reassurance that they can cast their vote according to political party. Likewise, if they want to reassert their trust in the individual regardless of the political party they are now associated with, that should happen in a by-election.

[John Lamont]

My hon. Friend is making an excellent speech. I do not want to downplay his greatness as a local constituency MP, but I am sure that, like me, he recalls the 2019 election in which he was first elected, and how many conversations we had with voters on the doorstep about the relative merits of the right hon. Member for Islington North (Jeremy Corbyn) and Boris Johnson as Prime Minister. That undoubtedly was the biggest issue driving many people to vote, alongside the desire to get Brexit done. Does that reinforce the point that many people vote on the basis of the national picture and to select a Prime Minister rather than a local MP?

[Robbie Moore]

That is my point. While a lot of us, as advocates of constituency areas, do our best day in, day out, advocating on behalf of our constituents and campaigning on the local issues that matter to give us the biggest advantage possible by building up our authenticity on those issues, a good proportion of the electorate vote based on the political party with which the candidates are associated.

In 2019, a good proportion of the electorate could not stand the possibility of a Labour Government and voted to get Brexit done, which we advocated for. I know from conversations on the doorstep that there was an element of the electorate who had never voted Conservative before, but who decided to vote for us in 2019 based on the national offering. That builds into my point that, whenever an individual defects—as happened recently north of the border, with the defection of a Conservative Member of the Scottish Parliament to the Liberal Democrats—a by-election should be triggered. It will be interesting to see what the Liberal Democrat policy is on that.

Trust is at stake, because too often disillusionment builds up among the wider electorate, and defections exaggerate that.

--- Later in debate ---

[Robbie Moore]

I thank the hon. Member for that point, but my point is that when a general election takes place, the individual voter casts their vote for an individual associated with a political party, which has a mandate—if it gets into power—based on a manifesto. The party leader’s name is not on the ballot paper. It is the manifesto that is associated with that political party. I do feel there is a difference.

I am strongly of the view that if an individual Member of Parliament associated with a political party decides to change course and stand for a different political party —crosses the Floor of the House—an automatic by-election should be triggered, which ultimately gives their constituents the right to choose. That is slightly different from the debate about political leadership, because a party leader’s name is not on the ballot paper; the name of the party is.

[John Lamont]

Having reflected on the point made by the hon. Member for Blackley and Middleton South (Graham Stringer), I would add that the key difference is surely that MPs are elected by their constituents, but the Prime Minister is appointed by the monarch, on the basis that that person can command the confidence of the House of Commons. That is the basis of the monarch’s decision. We do not have a presidential system, whereas we do elect constituency MPs. The appointment of the Prime Minister is based on the monarch’s judgment on who has the confidence of the House of Commons.

[Robbie Moore]

I thank my hon. Friend for his point, which I think aligns with my own point: it is the make-up of the political party that gains the confidence of the House, and therefore its leader is appointed Prime Minister, should they get a mandate to be so, based on the numbers.

Where I do not feel that a by-election should be triggered aligns with the points made by the hon. Member for South Cotswolds. If a Member of Parliament is unfortunate enough to lose the Whip and therefore sits in the House as an independent, I do not feel that that should necessarily trigger a by-election, because it might be subject to circumstances outside that Member’s control—political difference associated with a particular policy and therefore voting the other way. The Whips may use that as a mechanism for removing the party Whip, but I do not think that that should trigger a by-election in those circumstances. I want to be clear on that.

To summarise, politics is about trust, and at a time when the relationship between politicians and the electorate is, unfortunately, becoming increasingly fractious, it is vital that our democratic system holds us to account for the promises on which we as individuals associated with a political party were elected, the platform on which we chose to stand for election, and ultimately the manifesto commitments that we stood by.

--- Later in debate ---

[Lisa Smart]

No. The Liberal Democrat position is that elections should happen on a regular basis. We would re-implement the Fixed-term Parliaments Act 2011, because we think it is healthy for people to know how long they are electing somebody for, rather than leaving the power in the hands of the Prime Minister of the day. I believe very firmly that the ultimate power should sit with voters rather than politicians, and that voters should know how long the term is. They should be able to boot people out at the next election, rather than having a special election that costs money and that may end up with the same result, but may not. We do not agree with the petition. However, we believe very strongly in people’s right to express their views through a petition.

We need to change the system and the way we elect our MPs. Under our current system, a Government can win roughly two thirds of the seats on roughly one third of the votes. Millions of people are represented by someone they did not vote for. Seats bear almost no relation to votes cast, and far too many people feel forced to vote for the person they dislike the least just to stop the candidate they really do not want to be elected. Proportional representation would change that. The Liberal Democrats have been advocating for a change in our electoral system for a long time. We already use proportional systems in Scotland, Wales and Northern Ireland. The vast majority of democracies worldwide use them.

[John Lamont]

Will the hon. Lady give way?

[Lisa Smart]

If it is on the subject of PR, I will happily give way.

[John Lamont]

It is. Does the hon. Lady not recognise that we have had that debate in the UK? Part of Nick Clegg and David Cameron’s coalition agreement was a referendum on the alternative vote, and the British people rejected it in very large numbers.

[Lisa Smart]

I could not be more delighted to go into details about different voting systems. The hon. Gentleman will know that AV is a preferential system, not a proportional one. I am talking about proportional representation. AV would have been a better system than first past the post, but a proportionate system would be even better. It has long been in the Liberal Democrat manifesto that that would mean fairer representation and more people having their say.

--- Later in debate ---

[Anna Turley]

The hon. Gentleman is very impatient, because I was barely getting started on my speech. I will address that, because it is an important question that we have to challenge ourselves with, and it is right that we are here to debate it today, but I wanted to set out the primacy of party politics because, to me, it is about values. It is about what we believe in, and what kind of country and world we would like to build.

While I disagree fundamentally on many issues with Opposition Members, I recognise and respect that so many of them hold equally strong beliefs and values as those of us on the Government Benches, and that they are here to champion those party values in the name of public service, too. I appreciate—I am sure the hon. Gentleman will share this view—that when we cast our ballots at general elections, so many of us do so with a specific party manifesto, set of values or policy priorities in mind. People often elect the party that they want to govern based on a set of principles and priorities that they support or at least believe are preferable to those of the other parties.

As we have heard, people are also voting, albeit indirectly, for a particular Prime Minister. We cannot assume that the public do not see the weeks of general election coverage. The Prime Minister was on the front of our manifesto. People know that they are voting for a Prime Minister, because they know that the party with the largest number of MPs will send that person to 10 Downing Street.

When an elected MP leaves a political party, it is entirely understandable that voters may feel that the contract between them and their local MP has been broken, that trust has been broken and that a remedy, such as a by-election, is required to repair it. They may feel that they voted for that person not as an individual, but because of the shared values they believed they represented. They may feel strongly that they do not share the values of the new party that the MP has moved to. All of that is entirely understandable.

While I acknowledge why the petitioners—and, as we have heard, some in this place—may want to see a by-election to repair that, I believe that it is up to those MPs themselves to examine their conscience and their relationship with their voters, and not for this place to tell them what their principles should be. I have enough respect for and faith in the British public that, when that individual next goes back to their constituents to ask them for the sacred privilege, which we are so lucky to hold, of representing them in this place, the public will make their decision on the basis of all the evidence. They will decide whether that MP has their interests at heart, and whether they jumped ship out of principle—we have heard examples of that—or out of shameless political ambition. I will not point to any particular instances that we may have seen of that recently.

It is true that, while values tend to stay the same, parties can shift and evolve. I have seen that with my own party, as hon. Members have discussed. For example, in 2019, the British public had their say on whether they felt the Labour party had moved too far from where they were, or from where they felt we ought to be. Many people wrestled with that. Ultimately, we should have enough faith in the British public that they will assess the decision that their MP has made in defecting to another party and have their say. Some MPs have won after defecting to another party; others have lost. Ultimately, the public will weigh it all up and pass their judgment.

As the hon. Member for Keighley and Ilkley flagged, it is also important to remember that the public will make their judgment on the basis of a number of issues, not just the party allegiance of the MP. Despite the political differences I have with colleagues in this House, we have all come here to champion our communities and constituencies. Day in, day out, we support our constituents with casework issues, highlight the noteworthy work our local charities and organisations undertake across our communities, raise local issues closest to our constituents’ hearts and fix problems. As we all know, that vital work is personal to us individually, no matter which political party we come from. As such, much of the value of being an MP comes directly from our work with constituents, and they will ultimately price that into the decisions that they make.

It has been a long-standing constitutional principle in this country, most famously put forward by Edmund Burke, that MPs should deliberate and use their reason and judgment, as the hon. Member for Bridlington and The Wolds (Charlie Dewhirst) said, and not simply be a delegate of either party or populist opinion. A by-election on the basis of a defection would undermine that principle.

If we mandated that an MP must lose their seat the moment they leave their party, we would fundamentally alter the nature of our democracy. We would also shift from a system in which an MP’s first responsibility is to their constituents, to one where, once elected, they are accountable to their party’s leaders in Westminster. As the Prime Minister himself has said, “Country first; party second.”

[John Lamont]

I am grateful for the Minister’s analysis. I wonder whether she applies the same logic to her colleagues who have lost the Labour Whip because they have not complied with instructions to vote for Government policy that their constituents do not agree with.

[Anna Turley]

The hon. Gentleman raises a really important point. There is always a balance and a trade-off, which we all make as MPs, between that judgment and a sense of shared and collective responsibility. It comes back to the point I made at the beginning: we cannot achieve much on our own. We achieve much more when we are together, and political parties rise or fall on unity. It is for every MP to decide where their conscience lies. If they genuinely believe that their party is going against the principles and the will of their constituents, they have the opportunity to make that decision, but, ultimately, they must pay the price by losing the Whip. That is party discipline and collective responsibility. The hon. Gentleman raises a really important challenge, which we all think about often.

In the scenario that I described, in which we shifted to a system in which, once elected, an MP is accountable to their party’s leaders in Westminster, MPs who disagree with their party’s leadership, or feel that their political party is moving in a direction that they are uncomfortable with, may lose an important way to express their dissatisfaction. In the last Parliament, former MPs defected from the Conservative party because many felt that they were unable to deliver on the promises they made to their country. I understand the appeal of an automatic by-election to petitioners and to some Members of this House, but that would not make our parliamentary democracy stronger.

We must also consider the more practical impact of the petition’s proposal on our constituents. We all know the importance of our constituents having their own voices represented in Parliament. A by-election is a significant event. Members across the House know that it is costly to the public purse but, more importantly, it disrupts a constituency’s representation in this place. During a by-election campaign the seat is effectively vacant; casework stalls, the community loses its voice in Parliament for weeks or months, and the focus shifts to campaigning and the result’s implications for the Government of the day, rather than the issues that matter most to local residents.

Under our current system, when an MP changes affiliation, that work continues uninterrupted. The MP remains in post, serving their constituents and helping to support them with local issues. Naturally, that does not mean that MPs should be unaccountable for defecting to another party, but, as I have said, the remedy for that already exists in a general election. Of course, if an MP feels it is necessary to seek a fresh mandate, they are free to resign from both their party and their seat and fight a by-election immediately. I personally think that that would demonstrate an integrity that the public would welcome. In either case, the crucial thing is that MPs remain accountable to their constituents.

We do, of course, have a mechanism—

[John Lamont]

I apologise for disrupting the Minister’s flow, but I would like to ask her to clarify what she just said. She seems to be arguing that she is opposed to a by-election happening at the point of defection, but I think she hinted at a personal view that was contrary to the view that she had previously been articulating.

[Anna Turley]

Forgive me; my view, and that of the Government, is very clear. It is for each hon. Member to decide; it is not for the Government or Parliament to have a mechanism that forces people. People should examine their conscience: if they feel that a by-election would enable them to rebuild trust with their constituents, it is important that they consider that. However, it is not for Parliament to mandate that for those who defect. It is about integrity. If they believe that they have broken a promise that they made to people, then that is up to them.

We already have a mechanism to remove MPs during the course of a Parliament. Under the Recall of MPs Act 2015, by-elections are triggered by custodial sentences, suspension from the House or false expenses claims. Some have argued that we should add defection to that list, but I strongly urge against that. The core philosophy of recall is that it is triggered by conduct, not a change in values or even, dare I say it, political ambition. Of course, I agree that it is right that MPs who fall below ethical standards or break the law are held to account for their behaviour, but to conflate political disagreement or even naked opportunism with ethical misconduct would set a dangerous precedent. Finding oneself at odds with the direction of one’s party or wanting to jump on the latest populist bandwagon is not a lapse of behavioural standards; it is part of political life, and I believe the public can be trusted to see that and make a judgment for themselves.

The Government believe—and I believe too, just to clarify for the hon. Member for Berwickshire, Roxburgh and Selkirk (John Lamont)—that our current constitutional arrangements strike the right balance. They preserve much-needed stability in democracy and enable MPs who do change political parties to continue their vital constituency work, while reserving the public’s right to judge the work and principles of that MP at the ballot box. As chair of the Labour party and a proud member of this Labour Government, I strongly believe in political parties providing competing visions of the kind of world and the kind of country we would like to see and seeking a mandate from the public to enact them.

It is in the nature of our democracy, to support effective government in this country, that a party is able to command a majority in this House. Party values allow us to build our vision, turn our manifestos into reality, provide collective leadership and service, and enact the change that the country voted for at a general election. I understand why the petitioners and some Members across the House feel that an automatic by-election would add another layer of accountability in this place, but for the reasons I have set out, I do not believe that those changes would in any way enhance our parliamentary democracy.