Brexit: Theresa May promises to publish full impact assessment for deal she agrees with EU

Theresa May has promised she will publish an economic impact analysis of the final Brexit settlement she agrees with the EU, so that Parliament is “fully informed” before voting on the deal.

She made the pledge after a leaked document indicated the UK will be worse off outside the European Union with or without a trade deal, than it would if it stayed in.

Speaking to reporters on the way to an important trade visit to China, Ms May argued the leaked paper was a “very preliminary” analysis and had not tested the specific scenario she is seeking.

Asked by The Independent if she accepted it showed Britain would be worse off outside the EU under every scenario tested, Ms May said it would be wrong to describe the document as “the” Brexit impact assessment.

She went on: “There is analysis being done. This is very preliminary. What has been seen so far is a selective interpretation of a very preliminary analysis, which ministers have not signed off, have not approved, and which doesn’t actually even look at the sort of deal that we want to deliver in terms of the future relationship with the European Union.”

Pressed on why the deal the Government wants was not included in the analysis, Ms May then said: “When the time comes for Parliament to vote on the final deal, we will ensure that Parliament has the appropriate analysis on which to be fully informed, on which to base their judgement.

“But it would be wrong to publish analysis before that analysis has been completed, and it would also be wrong to publish analysis which might prejudice our negotiating position, and indeed Parliament itself has accepted that.”

Brexit minister Robin Walker later said the analysis would be provided to all parliamentarians on a "strictly confidential basis".

The paper, leaked to Buzzfeed, which was being briefed to Cabinet ministers this week, predicted that if the UK left the EU with no trade deal and reverted to WTO rules its GDP growth would be eight per cent lower over 15 years.

Even if the Government secured a free trade agreement, growth would still be five per cent lower, while if the UK remained in the single market after leaving the EU, growth would only be two per cent lower, the paper said.

Ministers have been heavily criticised over their reluctance to publish Government analysis of the impact Brexit will likely have on the British economy, with Cabinet minister David Davis previously forced to publish a range of sectoral analysis by a vote in Parliament.

Earlier this week chief EU negotiator Michel Barnier set out the bloc’s desired terms for the expected transition period between March 2019 and December 2020, in which the UK is likely to effectively remain in the single market and customs union, accept European Court jurisdiction and free movement.

As if that was not enough to annoy Conservative hard-Brexit backing MPs, Mr Barnier also poured cold water on British plans to negotiate free trade agreements during the transition and said the UK would have to accept new laws from Brussels, despite having no say in shaping them.

Bill Cash MP branded the EU demands an “ultimatum” and urged the Prime Minister to reject them, while John Redwood MP asked the Government to speed preparations for a ‘no deal’ Brexit in response.