Brexiteer Tories have come out against Theresa May’s plan to allow MPs to vote on a second referendum if they pass her EU-approved treaty, with some lawmakers calling for the prime minister to be ousted.

The Withdrawal Agreement Bill (WAB) is set to be voted on for a fourth time next month, and what was touted as a “bold offer” of concessions to win over Tory Remainers and the Opposition was branded as “dead on arrival” by Mark Francois, vice-chairman of the pro-Brexit European Research Group (ERG).

Tory Brexiteer Owen Paterson criticised the amended bill, saying that Mrs May had “managed to make the bad Withdrawal Agreement worse” and called it a “direct insult to the 17.4m people” who voted to leave in the referendum.

I listened carefully to the PM’s speech on the govt’s revised terms of Brexit. I cannot support legislation that would be the vehicle for a second referendum or Customs Union. Either option would frustrate rather than deliver Brexit – and break our clear manifesto promises. — Dominic Raab (@DominicRaab) May 21, 2019

Leave-backing leadership contenders also openly condemned the bill on social media, with Dominic Raab being the first to say that he “cannot support legislation that would be the vehicle for a second referendum or Customs Union.”

Front-runner in the leadership polls Boris Johnson soon thereafter tweeted that the bill directly contradicts the party manifesto and that he would not vote for it, saying, “We can and must do better — and deliver what the people voted for.”

Despite Johnson presenting as a Brexiteer, his sincerity has been questioned by Nigel Farage who stated this week that the heir apparent to the Tory throne had called May’s deal “vassalage” at the feet of the European Union, before duly voting in favour of it.

With great reluctance I backed MV3. Now we are being asked to vote for a customs union and a second referendum. The Bill is directly against our manifesto – and I will not vote for it. We can and must do better – and deliver what the people voted for. — Boris Johnson (@BorisJohnson) May 21, 2019

Chairman of the ERG Jacob Rees-Mogg echoed Mr Paterson’s sentiments that “the prime minister’s latest proposals are worse than before” and called for a no-deal, WTO exit.

Brexiteer Nadine Dorries called it “an utter betrayal of all we promised to deliver” with Andrea Jenkyns branding it a “farcical” demonstration of “how not to deliver Brexit.”

The deal is considered so far worse than previous iterations that even May loyalists like Stephen Crabb are reportedly expressing doubt that they can support it — pointing to an even greater defeat than the bill has seen in three earlier votes.

This Brexit Deal continues to betray the 17.4 million people who voted to leave. It fails to deliver the referendum mandate, our election manifesto commitments & is not in our national interest. More broken promises at a time when trust in democracy & politics is at its lowest. — Priti Patel MP (@patel4witham) May 21, 2019

While MPs have rejected en masse the bill which is most certainly to fail, a number have been vocal in calling for a new prime minister, with Mr Paterson saying, “If and when it is defeated, we need a new PM and Cabinet determined to leave the EU by 31st October at the latest.”

Mrs May survived a confidence vote in December and current party rules mean the prime minister is protected from another leadership challenge until December 2019; however members of the influential, backbench 1922 Committee are working to see if rules can be changed, the group expected to meet late on Wednesday afternoon.

The Prime Minister’s latest proposals are worse than before and would leave us bound deeply in to the EU. It is time to leave on WTO terms. — Jacob Rees-Mogg (@Jacob_Rees_Mogg) May 21, 2019

1922 member Nigel Evans told The Sun on Tuesday: “She has U-turned on absolutely everything. We cannot put up with this any longer.

“I will be asking my colleagues tomorrow to agree to a rule change so we can hold an immediate confidence vote if Theresa is not prepared to stand down now.”

“We are expecting there to be a new Conservative leader and prime minister within quite a short period of time,” Bernard Jenkin told media Tuesday night, “and I expect the new leader and prime minister to table what we call the Malthouse Compromise.

“That is the proposal to sort out the Irish backstop so at the very least the agreement we’re signing is something that we can leave at the end of the agreement period, we’re not locked into forever, and we’re not locked into an arrangement that threatens the unity of the United Kingdom, which is what Mrs May’s deal does.”