Theresa May's Brexit plan will deliver a 3.9 per cent hit to GDP and workers’ wages will be lower than if the UK stayed in the EU, according to the best estimate of government officials.

Every region of the country will be worse off in 15 years’ time, with London suffering the greatest damage, the analysis finds.

Real wages, after inflation, are expected to be 2.7 per cent lower – despite the claims of Brexiteers that cutting EU migration would allow pay to go up.

The analysis does not put a cash figure on the impact of a 3.9 per cent lower GDP, but other independent experts have suggested it equates to around £100bn – or £1,000 a head.

Such a sum would dwarf the gain from ending the UK's current contribution to EU budgets, which is only around £10bn a year.

The study assumes some “non-tariff barriers” in a future trade deal with the EU – in an apparent admission that the prime minister’s dream of “frictionless trade” is dead.

The 3.9 per cent figure also assumes new immigration controls result in no net flows of workers with the EU. With current flows, the reduction would be 2.1 per cent.

The long-term economic analysis also finds that borrowing could be pushed up by up to £26.6bn by 2035 under Ms May’s plans – and by as much as £119bn under a no-deal Brexit.

Cabinet ministers resign over Brexit deal Show all 13 1 /13 Cabinet ministers resign over Brexit deal Cabinet ministers resign over Brexit deal Esther McVey Britain's Work and Pensions Secretary Esther McVey arrives to attend the weekly meeting of the cabinet at 10 Downing Street in London. - Britain's Work and Pensions Secretary Esther McVey resigned from the cabinet over draft Brexit deal AFP/Getty Cabinet ministers resign over Brexit deal Handout image taken from the Twitter feed of @EstherMcVey1 of the resignation letter addressed to Prime Minister Theresa May from Works and Pensions Secretary Esther McVey. PRESS ASSOCIATION Photo. Issue date: Thursday November 15, 2018. Ms McVey has resigned, saying the Brexit deal âdoes not honour the result of the referendumâ. See PA story POLITICS Brexit. Photo credit should read: @DominicRaab/PA Wire NOTE TO EDITORS: This handout photo may only be used in for editorial reporting purposes for the contemporaneous illustration of events, things or the people in the image or facts mentioned in the caption. Reuse of the picture may require further permission from the copyright holder. PA Cabinet ministers resign over Brexit deal Dominic Raab British Brexit Secretary Dominic Raab give a press conference at the end of the final round of talks in Brexit negotiations at the European Commission in Brussels, Belgium EPA Cabinet ministers resign over Brexit deal Handout image taken from the Twitter feed of @DominicRaab of the resignation letter addressed to Prime Minister Theresa May from Brexit Secretary Dominic Raab. PRESS ASSOCIATION Photo. Issue date: Thursday November 15, 2018. Mr Raab has resigned, saying he âcannot in good conscience support the terms proposed for our deal with the EUâ. See PA story POLITICS Brexit. Photo credit should read: @DominicRaab/PA Wire NOTE TO EDITORS: This handout photo may only be used in for editorial reporting purposes for the contemporaneous illustration of events, things or the people in the image or facts mentioned in the caption. Reuse of the picture may require further permission from the copyright holder. PA Cabinet ministers resign over Brexit deal Rehman Chrishti Vice Chairman of the Conservative Party Rehman Chrishti tendered his resignation letter this afternoon PA Cabinet ministers resign over Brexit deal Cabinet ministers resign over Brexit deal Anne-Marie Trevelyan Parliamentary private secretary in the Department of Education Anne-Marie Trevelyan resigned stating that she cannot support the deal Cabinet ministers resign over Brexit deal Handout image taken from the Twitter feed of @annietrev of the resignation letter addressed to Prime Minister Theresa May from Anne-Marie Trevelyan, a parliamentary private secretary in the Department for Education. PRESS ASSOCIATION Photo. Issue date: Thursday November 15, 2018. Ms Trevelyan has resigned saying she cannot support the Brexit deal after negotiations âbuilt on the UK trying to appease the EUâ. See PA story POLITICS Brexit. Photo credit should read: @annietrev/PA Wire NOTE TO EDITORS: This handout photo may only be used in for editorial reporting purposes for the contemporaneous illustration of events, things or the people in the image or facts mentioned in the caption. Reuse of the picture may require further permission from the copyright holder. PA Cabinet ministers resign over Brexit deal Sam Gyimah Universities minister Sam Gyimah resigned on November 30, claiming the government's decision to pull out of the EU's Galileo satellite navigation system as a deciding factor PA Cabinet ministers resign over Brexit deal Shailesh Vara Shailesh Vara who has quit as Minister of State for Northern Ireland, saying he cannot support Theresa May's Brexit agreement, which he said "leaves the UK in a halfway house with no time limit on when we will finally be a sovereign nation" PA Cabinet ministers resign over Brexit deal Cabinet ministers resign over Brexit deal Suella Braverman Brexit minister Suella Braverman has resigned, stating “It is not what the British people, or my constituents, voted for in 2016.” Cabinet ministers resign over Brexit deal Ranil Jayawardena Parliamentary private secretary to the ministry of justice Ranil Jayawardena resigned as he could not back the deal "in good conscience"

However, it acknowledges officials are working largely in the dark, after the prime minister admitted future trade arrangements are unknown – and after the EU threw out her Chequers plan.

David Lammy, a Labour supporter of the anti-Brexit Best for Britain group seized on the study, saying: “These figures show that the government's stated policy is to make our economy smaller and weaker.”

Arguing it strengthened the case for a Final Say referendum on the Brexit outcome, he added: “I cannot believe leave or remain voters both voted to make themselves and their families worse off.”

The 83-page document was drawn up by officials from departments including the Treasury, the department for exiting the EU, industry, environment, international trade and the home office.

It was released after Philip Hammond, the chancellor, admitted Britain would be poorer under Ms May’s plans, saying: “There will be a cost to leaving the European Union, because there will be impediments to our trade.”

The prime minister is heading to Scotland in her latest attempt to win support for a deal that appears to be heading to a crushing defeat in the Commons on 11 December.

Significantly, the analysis suggests the UK will be poorer under Ms May’s plans than under the ‘Norway-plus’ option – staying in the EU single market – being considered by some senior Tories.

A Norway-type deal would cut GDP by 1.4 per cent over 15 years – less than the 3.9 per cent hit from the current plan – and less than a Canada-type free trade agreement (6.7 per cent) or crashing out with no deal (9.3 per cent).

The modelling includes a heroic assumption that “successful” bilateral trade deals will be struck with 17 other countries, including the US, China and India.