British MPs have defeated the Government on an amendment which could thwart efforts by the next prime minister to force through a no-deal Brexit.
The Commons backed the move by 315 votes to 274, majority 41, which could stop the next PM suspending Parliament in order to allow the UK to crash out of the EU.
A source close to Tory leadership contender Jeremy Hunt said the Foreign Secretary was given permission not to take part in the vote, however his rival Boris Johnson voted against the move to block prorogation.
Margot James, minister for digital and the creative industries, rebelled by supporting the amendment.
The vote came after the Lords strongly backed a bid to block Parliament being suspended in order to facilitate a no-deal exit by a margin of 103 votes on Wednesday.
The change to the Northern Ireland (Executive Formation) Bill will require progress reports on restoring devolved government in Northern Ireland to be debated regularly in Parliament, effectively preventing it being prorogued.
Justice Secretary David Gauke said before the vote that proroguing Parliament would be “outrageous” – but he did not confirm whether he would back the measures to block it.
He told BBC Radio 4’s Today programme: “At a crucial point in this country’s history, if you like – that Parliament should not be able to sit, should not be able to express its opinion and its will, I think would be outrageous.
“I very much doubt that any prime minister would in fact suspend Parliament in these circumstances, but I can understand the concerns that a lot of my colleagues have.”
Downing Street said forcing a report and debate every two weeks risks being “counter-productive” to the aim to restore the executive in Northern Ireland.
The Prime Minister’s official spokesman told a Westminster briefing: “We have been very clear that the purpose of this Bill is to ensure the continuation of vital public services and effective governance for the people of Northern Ireland.
I very much doubt that any prime minister would in fact suspend Parliament in these circumstances
“In the light of the ongoing talks to restore the Executive, our view is that forcing a report and debate every two weeks on the progress of those talks risks being counter-productive to this overarching aim.”
Front-runner for the Tory leadership Mr Johnson again refused at the final campaign hustings on Wednesday to rule out proroguing Parliament in order to meet his red line of getting the UK out of the EU by October 31.
Mr Hunt has insisted he would not use such a constitutional manoeuvre.
The amendment to the Northern Ireland (Executive Formation) Bill builds on an amendment passed in the Commons last week, when MPs backed a proposal from the pro-European Tory Dominic Grieve calling for fortnightly reports from the Government on the efforts to restore the powersharing executive.
The new Lords amendment would ensure these have to be debated in the weeks before the Brexit deadline.
The Bill could theoretically make it illegal for the Government to prorogue Parliament in the autumn if the powersharing executive in Northern Ireland has not been restored.