Senior MPs who forced Theresa May to delay Brexit by seizing control of parliament are “optimistic” they have a workable plan to block a new Tory leader pursuing no deal without triggering an election.

The cross-party group, led earlier this year by Yvette Cooper, Nick Boles and Sir Oliver Letwin, have already been working on how to stop Boris Johnson or Dominic Raab dragging the UK out of the EU with no deal against MPs’ will on October 31.

Earlier this year, the powerful collective of former ministers and select committee chairs were able to seize control of the Commons to pass their own legislation in just one day to direct May to delay Brexit beyond March 29.

The group acknowledges that it is unlikely to be able to use a similar process because there are no major scheduled votes on Brexit.

But they are confident they have found a means to stop no deal, even amid Raab’s suggestion he may prorogue (meaning to effectively suspend) parliament to stop MPs blocking Brexit.

Boles told HuffPost UK the plan is more sophisticated than simply collapsing the government in a vote of no confidence, which may prove difficult because Tories would have to vote against their own party and trigger an election which could see them lose their seats.

Commons Speaker John Bercow has previously hinted he could allow MPs to use emergency debates, which normally do not include votes, to pass motions or amendments.

But Boles remained tight-lipped on the group’s strategy.

The former minister, who quit the Tories after his plan for a soft Brexit failed, told HuffPost UK: “We have been working on it.

“The route we used before is not available but we are cautiously optimistic that we will be able to find another.

“I can’t say more at this point.”

Liberal Democrat former minister Norman Lamb, a senior backer of the original group, said he expected Speaker John Bercow to bend parliamentary convention to allow MPs an opportunity to block no deal.

“I’m acutely aware that Bercow wants to facilitate parliament having its voice heard and given that an awful lot of this was supposed to be about parliamentary sovereignty, the idea that parliament in any way should be circumvented is abhorrent and intolerable,” Lamb said.

“And it may involve novel interpretations of procedure but the principle that parliament must actually have its say is paramount.”

He urged MPs to urgently finalise contingency plans to stop no deal, suggesting the Tory leadership race, which is due to finish at the end of July, could be shortened if one candidate looks unassailable and everyone else drops out.

“It’s quite dangerous because can just drift by,” he said.

“If we don’t know who the new leader is until very shortly before recess and then we’re into recess and then we’re back into that crisis mode again in the period running up to the end of October.”

He added: “There does need to be a refocusing but it’s so difficult without knowing what’s going to emerge from the Tory leadership – but we are going to need to make contingency plans.”

It came as Letwin revealed he was backing Michael Gove, who has said he is open to delaying Brexit again if there is the prospect of a better deal, for the leadership.

The ex-cabinet minister said Gove would provide “the highest chance of exiting the EU with a sensible deal”.

Home Secretary Sajid Javid meanwhile became the latest Tory leadership candidate to denounce the idea of proroguing parliament, calling it “anti-democratic and anti-British”.

Javid said that while he wanted to leave the EU by the cut-off date of October 31, he accepted Parliament was entitled to a say.

“I wouldn’t prorogue parliament. That is a complete nonsense. My policy would be to do everything I can to leave the European Union on October 31,” he said.

“If it got to a point where I had to choose between no-deal or no Brexit, I would pick no-deal. But whatever I do, parliament is going to want to have its say on it and parliament should have its say. 

“Our parliament is sovereign. I am not into this proroguing parliament rubbish. It is just a complete nonsense and anti-democratic and anti-British.”