Theresa May promised a “robust” response to Lords defeats over Brexit amid concern from her ministers that peers were seeking to “thwart” the UK’s departure from the European Union.

At a Cabinet meeting, ministers expressed their “strong disappointment” at measures passed by the Lords which risked “tying the Government’s hands behind its back in negotiations with Brussels”, Downing Street said.

International Trade Secretary Liam Fox has suggested peers were using a “backdoor mechanism” to delay exit from the EU “indefinitely”.

Liam Fox is one of the Government's most prominent Brexiteers (Jonathan Brady/PA)
Liam Fox is one of the Government’s most prominent Brexiteers (Jonathan Brady/PA)

In a blow to Mrs May’s Brexit plans, the House of Lords voted to give Parliament a decisive say on the outcome of the negotiations.

Asked about the Lords vote, the Prime Minister’s official spokesman said: “There is a role for it to play in providing scrutiny, but the British public have voted to leave the European Union and Parliament needs to get on and deliver that.”

In an indication the Government will seek to overturn the defeat when the European Union (Withdrawal) Bill returns to the Commons, Mrs May told her Cabinet “the Government would be robust”, and it was “vital to ensure that the legislation is able to deliver the smooth Brexit which is in the interests of everybody in the UK”.

But Labour leader Jeremy Corbyn suggested his MPs would seek to retain the extra powers for Parliament sought by the Lords, telling the BBC: “I think Parliament should have the final say on the terms of leaving the European Union, and if we don’t accept the decisions that the Government has made, then they should be sent back to negotiate again.”

Dr Fox, one of the most committed Brexiteers in Cabinet, was scathing about the Lords vote – one of three defeats on Monday night.

He told BBC Radio 4’s Today programme: “We can’t have a situation where the clearly expressed will of the people in a referendum is thwarted by effectively procedural devices that would keep us in the EU indefinitely.”

He added: “I think there is quite a big debate now about whether the unelected House can actually thwart the view of the British electorate in a referendum and what’s been happening in terms of the legislation coming from the House of Commons.”

Dr Fox denied that a string of parliamentary defeats being inflicted on the Government would eventually force it into accepting that the UK would have to be part of some form of customs union with the EU – something Mrs May has previously ruled out.

His comments come ahead of a crunch meeting of the Cabinet’s Brexit sub-committee, which will decide on the UK’s approach to future customs arrangements.

“I don’t think there is a customs union that could ever be acceptable,” he said.

“If we are in a customs union of any sort we will have less ability to shape Britain’s future than we have today. That is not what the public voted for.”

Dr Fox refused to say whether he would quit if Mrs May changed course, adding: “Getting no answer you can draw your own inferences.”

Former deputy prime minister Lord Heseltine and ex-ministers Lord Patten of Barnes and Lord Willetts were among 19 Tory rebels to support the cross-party amendment calling for Parliament to be given the decisive say on whether to accept the Brexit deal.

In a sign of the difficulties potentially facing the Prime Minister in the Commons, senior Tory backbencher Sarah Wollaston said Brexiteers wanted to “take back control” to the UK, but “Parliament won’t support a hard Brexit”.

Fellow Tory Heidi Allen said the Lords were “merely reflecting what the majority of MPs believe – that Parliament must have a say in whether the deal is good enough”, and a no-deal scenario “never will be”.