Diego Garcia Military Base and British Indian Ocean Territory Bill

Lord Altrincham Excerpts

3rd reading
Monday 12th January 2026 Lords Chamber

[Baroness Goldie (Con)]

My Lords, I first of all associate myself with the remarks of my noble friend Lord Callanan. I preface my further remarks by saying there was a very useful debate on Report, which brought out a number of important points which command attention. In that context, I spoke then exclusively on the defence and security implications of this treaty. I thank the Minister, the noble Lord, Lord Coaker, for both listening to my concerns and undertaking to write to me, which he has indeed done. That attentive and helpful approach bears all the hallmarks of a responsible and helpful persona which a Defence Minister should be, and of which the noble Lord, Lord Coaker, is the embodiment; the content of the response bears all the hallmarks of a letter drafted by someone blind to the basic precepts of defence and security but who finds much more comfortable the languorous corridors of the FCDO and the limiting confines of the minutiae of the text of this treaty.

It is the other treaty, the Pelindaba treaty, about which I sought clarification. Instead, I received a letter about how this treaty guarantees this, stops that and binds Mauritius to the other. The letter is silent on how, once Mauritius gains sovereignty of the Diego Garcia base under this botched treaty, Mauritius can stop the co-signatories of the Pelindaba treaty, either on their own account or egged on by others, from challenging Mauritius on alleged misuse of the base under the terms of the Pelindaba treaty. I suspect the reason for the silence is because you cannot stop that third-party interference.

That strikes at the heart of why we currently have sovereignty over the base, how we use it, how the United States uses it and how our allies may need to use it. That unfettered, unchallengeable usage and access is possible only because we have sovereignty. While we can have bilateral discussions with Mauritius and enter into bilateral agreements and treaties with Mauritius, they are only as good as Mauritius has competence to give the protections, undertakings and reassurances. If the hands of Mauritius are tied by a preceding undertaking such as the Pelindaba treaty, then these protections, undertakings and reassurances are not worth the paper they are written on—just a load of flummery.

I did not put down an amendment at Report, because this flaw is irremediable. I was prepared to allow the Government a final opportunity to provide clarification and reassurance, but, unsurprisingly, they have been unable to do that. The question then is: what should a responsible Opposition do? My naturally bellicose nature inclined towards voting against this Bill, but I am not indifferent to the constitutional status of this House and the respective conventions which regulate our proceedings in relation to government Bills. Fortunately, my leader, my noble friend Lord True, and my Chief Whip, my noble friend Lady Williams of Trafford, are far less hot-headed than I am and infinitely more thoughtful and strategic in outlook. It is their view, which I accept, that, however wrong-headed and naive we think this treaty to be, voting down the Bill on Third Reading is not an appropriate way, in this instance, to proceed.

Our regret Motion places on the record all our misgivings and apprehensions. If this precarious, ill-starred government adventure comes to grief, it will give me no pleasure to say, “We told you so”, but at least His Majesty’s Opposition can hold their head up and say, “We did our job”; what a pity the Government cannot make the same claim. I support the amendment in the name of my noble friend Lord Callanan.

[Lord Altrincham (Con)]

I thank the Minister for her courtesy and patience throughout this very unusual Bill and its passage through this House. I will make a few remarks on the financial costs.

The treaty makes provision for a financial agreement that requires the UK to make payments to the Republic of Mauritius for the next 99 years. The agreement is very unusual, and that is because the payments are not known. The payments are not known from year 14 for the next 85 years because the payments are linked not to events in the Indian Ocean but to UK domestic inflation. It is an extraordinarily long contract for the taxpayer to be exposed like this to UK domestic inflation.

Inflation in the future is unknown, unknowable and uncapped. That means the payments under this contract are unknown, unknowable and uncapped. Maybe the Foreign Office, in looking at the projections, imagined a very benign opportunity for UK inflation and maybe it hoped that the numbers would stay very low, but if we had inflation as high as it was in this country two years ago, at any point in the 85 years of this contract the payments would get completely out of hand and be completely unaffordable to the UK.

This is why Ministers and Parliament have been poorly briefed on the contents of the treaty and why there is this extraordinary difference between the £3.4 billion accounting valuation, which was done under the Treasury Green Book procedure for UK domestic infrastructure spending, and what this is actually going to cost. As my noble friend Lord Callanan mentioned, the Government’s own internal estimate of the cost is around £34 billion to £35 billion, which is a very substantial amount to be paying.

We might hope, at this stage of the Bill, to have some good advice from the OBR, but the OBR has been quite unhelpful to the Government—and, possibly, to Parliament—and said that it has nothing to do with this. We might hope for clarification from His Majesty’s Treasury. Of course, the treaty was not negotiated by the Treasury; it was negotiated by another department. But, in the middle of the holidays, the Chief Secretary to the Treasury slipped out an announcement on 16 December—it is on GOV.UK—to say that the Treasury would be changing its Green Book methodology. So, we can be sure that the Treasury does not even agree with the accounting valuation, let alone the actuarial true cost of this agreement.

When the Minister said to us during the passage of the Bill that the total cost was £3.4 billion—she said it to us in this Chamber—it was not correct, because the total cost is not known. That needs to be corrected in the treaty, because it is quite clear that that is the intention of the Government. The Government wish, for their own reasons, not well understood by the Opposition, to pay the Republic of Mauritius £3.4 billion. It is their intention and it appears to be their understanding—but it is not what is in the treaty.

[Lord in Waiting/Government Whip (Lord Leong) (Lab)]

My Lords, this is Third Reading. Arguments made at previous—

[Lord Leong (Lab)]

This is Third Reading and the noble Lord is repeating what has been debated before.

[Lord Altrincham (Con)]

I will speak briefly to the rest of the amendment.

The amounts referenced in the Chamber and during the passage of the Bill have not been correct. We need to make sure that the treaty is amended to reflect what the Government’s intention is: that it should be a payment of £3.4 billion and not an open-ended economic exposure. Given the extremely unusual and long-dated nature of this contract, we need to make sure the treaty is amended to protect UK taxpayers and, indeed, to maintain confidence in the sovereign credit of the UK.

[Lord Weir of Ballyholme (DUP)]

My Lords, I join with others in welcoming the robust yet civilised and courteous way in which this legislation has been debated. Obviously, at Third Reading, it is not appropriate to regurgitate all the arguments. However, given the significance of the Bill, it is also the case that it merits some level of, albeit brief, comment. While we have gone through this process, and I welcome the amendments that have been tabled to the Bill, they cannot render acceptable what is totally unacceptable.

We are still left with a Bill that is bad for the United Kingdom. We are not simply handing over sovereignty to Mauritius; we are paying it an expensive dowry to take over what has been British sovereign territory for 200 years.

From a defence point of view, we are left with a flawed situation. Rather than perhaps the jewel in the crown, we are left with a situation where, despite the assurances that have been given, we know, from a practical point of view, that we will see Mauritius in effect leasing out, in either official or unofficial form, to foreign powers—particularly the Chinese Government—surrounding islands. So, instead of a jewel in the crown, we will be left with a military base with a noose around it, ever tightening as time moves on.

In particular, even with the amendments, we have not dealt with the situation as regards our debt and duty to the Chagossians themselves. We have been left in a situation in which they have been denied complete access to the islands. They have no right of full self-return. More importantly, they have also been left without the right of self-determination.

This House has been united, as we saw a few moments ago, in rightly condemning what has been happening in Iran and supporting the Iranian people in their right of self-determination. This House, on a number of occasions, has utterly condemned the invasion of Ukraine and supported the right of Ukrainians to decide their own future. Similarly, I suspect that this House would be united in saying that the Greenlanders have the right to determine their own future and that it should not be imposed from the United States or anywhere else. The thread that runs through all three of these situations is the right of self-determination and democracy. That is the golden thread to which should be standing.

Yet, we are in a situation, as regards the Chagossians, that this can apply elsewhere in the world but, shamefully, not to the people who have actually looked to us to deliver for them. If we simply let this go through and the Government let this go through unaltered, we will lack the moral or political authority to dictate elsewhere in the world on the issue of self-determination. So I support the regret amendment in the perhaps vain hope that, by sending a signal today, we can at least say to the Government, “Think again before it is entirely too late”.