Britain’s interests will be “repeatedly and permanently hammered” if it leaves the European Union under Theresa May’s Brexit plan, Sam Gyimah said as he became the seventh cabinet minister to resign over the agreement.

Stepping down from his post as universities minister, he said the government’s plan was “not in the British national interest” and voting for it would “set ourselves up for failure” by surrendering “our voice, our vote and our veto”.

“Britain will end up worse off, transformed from rule makers into rule takers,” he said in a resignation letter which he posted to on his Facebook page. “It is a democratic deficit and a loss of sovereignty the public will rightly never accept.”

His departure underlines the uphill task the prime minister faces if she is to win the crunch vote in the Commons on the deal on 11 December.

Earlier, Ms May, in Argentina for the G20 summit, brushed off questions over whether she would resign if she was defeated in the Commons.

“I have been asked these sorts of questions before,” she told reporters.”I’m tempted to think the price of coming on one of these trips is asking questions about my future, because they come up every time and my answers aren’t going to change.”

However the latest ministerial resignation by an MP who was among her early supporters for the leadership leaves her looking increasingly exposed.

Other senior ministers to resign include former Brexit secretary Dominic Raab, former work and pensions secretary Esther McVey and ex-Northern Ireland minister Shailesh Vara. A number of junior ministers also resigned over the deal.

Mr Gyimah said a deciding factor in his resignation was the EU’s continued squabbling over the Galileo satellite navigation system.

Britain has given up efforts to gain access to the project for defence and critical national infrastructure purposes after being frozen out by Brussels because of Brexit.

It is unclear whether the UK will get back the £1.2bn already sunk into the project and could face a potential £5bn bill for a new system.

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"

Mr Gyimah said “we shouldn’t dismiss out of hand the idea of asking the people again what future they want, as we all now have a better understanding of the potential paths before us”.

The Independent has launched its Final Say campaign to demand voters are given a voice on the final Brexit deal.

The East Surrey MP said “there is a mountain to climb, and we are still in the foothills” and warned “our interests will be repeatedly and permanently hammered by the EU27 for many years to come”.

He added that her “compromise” agreement would not bring the country back together as she hoped and he urged her not to “dismiss out of hand” the option of a second referendum.

“What is being presented to the public as a sensible compromise Brexit deal, a 52/48 Brexit as some call it, will not bring closure or heal the divisions of Brexit,” he said. ”In the fullness of time, the public will wake up to what this so-called deal entails; neither leave nor remain voters will be pleased with a deal that leaves us poorer, less secure and weaker in the pursuit of our national interests.”

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Responding to his resignation, Liberal Democrat education spokesman, Layla Moran said: “This government is falling apart and the decision must be taken back to the public. We know May cant win on the 11th, Sam Gyimah shows us that her deal can’t even convince those closest to her.

”As universities and science minister Sam Gyimah will have seen at close quarters the devastating effect this botched Brexit will have on these important sectors. He should be applauded for his actions today and for also not discounting a People’s Vote.”

The prime minister received support from environment secretary Michael Gove – one of the leaders of the Leave campaign – who urged Tory Brexiteers to get behind the agreement.

In an article for the Daily Mail, he warned that Brexit could be “in peril” if the agreement was voted down.