Question to the Department for Exiting the European Union :

To ask the Secretary of State for Exiting the European Union, what estimate he has made of the potential cost to UK companies of (a) tariffs and (b) non-tariff barriers on exports if the UK leaves the customs union.

It is in both the UK and EU's interest to see tariff-free trade and for that cross-border trade to be as frictionless as possible. We will pursue a bold and ambitious trade agreement with the EU and also a new customs agreement. We have an open mind on the form of any customs agreement.

The government is conducting a broad range of analysis at the macroeconomic and sectoral level to understand the impact of leaving the EU on all aspects of the UK. But we are not going to publish any assessment of the impacts of potential courses of action that could undermine the UK’s negotiating position.