The future of the House of Lords could be in doubt as peers are “playing with fire” by trying to thwart Brexit, Jacob Rees-Mogg has warned.

The Tory MP, leader of the influential European Research Group of Conservatives, said it was now a case of the “peers against the people” after the Government’s Brexit legislation suffered a series of defeats in the upper chamber.

His comments came after a petition calling for a referendum on abolishing the House of Lords passed the 100,000 signature mark, which could trigger a debate in Parliament.

Mr Rees-Mogg, speaking in Parliament at an event organised by the Open Europe think tank, said peers “have to decide whether they love ermine or the EU more”.

In a series of forthright interventions, Mr Rees-Mogg:

– Said giving preferential immigration treatment to EU citizens after Brexit would be a “racist” policy

– Described Theresa May’s approach to Brexit as “enigmatic”

– Labelled the Government’s proposal for a customs partnership with the EU “completely cretinous”

The Government’s plans for Brexit have been dealt a series of blows in the Lords, with peers inflicting a massive defeat on the issue of leaving the customs union.

Mr Rees-Mogg claimed that peers were breaching the convention that the House of Lords should not prevent a Government implementing commitments made in its election manifesto.

And he said the Prime Minister had made it “absolutely clear” that she would not accept remaining in a customs union after Brexit.

The Government is expected to try to overturn the amendment in the Commons and Mr Rees-Mogg warned would-be Tory rebels: “I don’t think it’s fine for people to tell their voters they are standing to leave the customs union and then not to do that.”

In a message to the peers he accused of seeking to “thwart” the referendum result, Mr Rees-Mogg said: “It’s striking that 100,000 people can sign a petition so quickly.

“I think their lordships are playing with fire and it would be a shame to burn down a historic house.”

A petition calling for a referendum on the future of the Lords has passed 100,000 signatures
A petition calling for a referendum on the future of the Lords has passed 100,000 signatures

Mr Rees-Mogg played down the prospect of the Government collapsing over the customs union issue, insisting that when it came to a vote in the Commons it would not be a confidence motion.

He rejected the suggestion that a defeat would be so damaging for Mrs May’s authority she would have to stand down.

“I think when you have got a very small majority you accept that you won’t always get every vote that you want, and you have to look at the legal effect of what happens.”

Theresa May's attitude to Brexit is
Theresa May’s attitude to Brexit is “hard to read”, Jacob Rees-Mogg said (Victoria Jones/PA)

He said the Prime Minister’s attitude to Brexit was “hard to read”, but it was a “good thing” to have a leader who exercised self-control.

“The Prime Minister is a very enigmatic figure in this respect. She is carrying out the will of the British people but it’s hard to read what level of enthusiasm she has for it.

“She is doing it, she has never indicated anything other than that, she said ‘Brexit means Brexit’, but she doesn’t – by her nature – express herself unduly emotionally.

“I think that’s rather a good thing. I like having a Prime Minister who is able to exercise a good deal of self-control.”

The North East Somerset MP said if he was in the negotiations with Brussels he would be “much firmer and clearer about the costs to the EU” of a “no deal” scenario – which could leave the bloc “insolvent” without the UK’s money and risk crippling the Irish economy.

And he mocked the idea of a customs partnership, one of the two options put forward by the UK to deal with future customs arrangements.

The “completely cretinous” idea would see the UK collect tariffs on the EU’s behalf for goods landing in Britain but intended for the bloc’s market, something Mr Rees-Mogg said would be “impractical, bureaucratic” and “a betrayal of common sense”.

Mr Rees-Mogg, who has been tipped as a potential successor to Mrs May, played down his prospects.

“When the Conservative Party is in government, the prime minister always comes from a senior government position and that is a perfectly sensible state of affairs,” he said.

Responding to Mr Rees-Mogg’s comments, Prime Minister Theresa May’s official spokesman said that it was part of the Upper House’s role to scrutinise legislation.

But he added: “We have been clear that we are disappointed with the decisions which have been taken by the House of Lords. We believe that the Withdrawal Bill was passed by the House of Commons and was passed in a way which would allow us to deliver the smooth Brexit which the country wants.”

The spokesman added that the Government had already set out its plans in relation to House of Lords reform.

Asked whether he would agree that Mrs May had been “enigmatic” about her views of Brexit, the spokesman said: “The Prime Minister has made absolutely clear her determination to deliver on the will of the British people, and that she believes that we can deliver Brexit in such a way that provides for Britain a stronger, more prosperous and more secure future.”