The new chairman of the hardline Eurosceptic Tory faction has urged Boris Johnson to do a deal with Nigel Farage’s Brexit Party if there is an election before Britain leaves the EU or “lose Brexit”.

Steve Baker, who was elected chair of the European Research Group (ERG) on Tuesday, also vowed to oppose the Brexit deal even if the prime minister manages to remove the Irish border backstop.

And he criticised Johnson’s threat to treat hardline Leavers the same as MPs ranged against a no-deal Brexit – by sacking them if they vote against any new withdrawal agreement.

Baker’s hardline stance creates a new headache for Johnson as he grapples with a rebellion which threatens to take control of the parliamentary agenda away from him as MPs look to block a no-deal Brexit on October 31.

If Johnson loses Tuesday night’s Commons takeover vote he has said he will be forced to call an election to take place on October 14, two weeks before Brexit.

Baker repeated his past insistence that the Tories would have to do a deal with Farage’s Brexit Party, which is campaigning for a no-deal withdrawal from the EU, to stand a chance of winning that election.

“If we have an election before we have left the European Union and the Brexit Party think that we’re heading in a direction which does not deliver our independence from the EU then they will stand candidates virtually everywhere and the result will be as per Peterborough and in Wales, they will result in a Lib/Lab Remain coalition, we will lose Brexit,” he said.

The PM spent Tuesday trying to convince anti-no deal MPs he has a plan to remove the backstop, an insurance policy to maintain an invisible border on the island of Ireland, and get a new Brexit deal.

But Baker, who once introduced himself on Sky News as “Brexit hardman Steve Baker”, said he was “absolutely clear” that time-limiting it, or even removing it from the deal, would still not be enough for him to vote for it. 

Taking a much harder line than his predecessor Jacob Rees-Mogg, who is now in the cabinet and voted for Theresa May’s deal on the third occasion, Baker said: “I have no intention of voting for this withdrawal agreement and it’s not adequate to me if all they do is remove the backstop.

“I believe that Boris Johnson is very clear in his understanding that the backstop is not the only problem with the withdrawal agreement.

“And the reason for that is he keeps saying that the withdrawal agreement is dead.”

Baker also suggested he was willing to be sacked from the Tory party to vote against the Brexit deal.

It came after Johnson said he would fire Brexiteers who oppose any new deal, to match his threat to remove the whip and ban from standing for election any Tory MP who votes to hand control of the Commons to the opposition and backbenchers on Tuesday night, to stop no deal.

“I have already said that if all they did was get a time-limit on the backstop which I have reason to believe Merkel and Macron would be willing to offer, which Boris Johnson has said would be unacceptable, if that’s all they do I have already said I would vote against it come what may,” Baker said.

He also criticised Johnson’s threat, suggesting it would fundamentally change the role of an MP, and urged the PM to row back.

The ERG chair said Tuesday’s Commons takeover vote was rightly a confidence matter as it would take away the government’s ability to govern if passed.

But MPs have long been able to “vote against a policy issue” like the Brexit deal and “take political consequence short of losing the whip”.

Baker said: “It’s at least a change of emphasis and the privileges of an MP, certainly nobody would be able to tell you how to vote but if you know on any vote if you rebel you lose the whip, that’s a very different relationship between the MP, the party and the voter and I would not support that change,” Baker said.

“So I watched Boris give that answer on TV, he obviously felt he had to give that answer, I think the escape from the trap that he is in at this point is to make it very, very clear that there has always been a difference between votes which are confidence votes and votes on issues of policy.”