MPs backed an amendment, 315-274, designed to make it much more difficult for the next Prime Minister to suspend Parliament to force through No Deal.
Boris Johnson has refused to rule out “proroguing” – suspending – Parliament just before October 31 to stop MPs blocking a No Deal Brexit .
But today’s amendment will force Parliament to meet – in theory to discuss unrelated issues about Northern Ireland – even if it has been prorogued.
Several Tories backed the amendment with at least one minister, Margot James, resigning to support it.
The amendment is not an outright ban on suspending Parliament, but would make it much more difficult to do so.
Furious Northern Ireland minister John Penrose branded the amendment – to the unrelated Northern Ireland Bill – a “stitch-up”.
He told MPs: “Not only is this amendment dangerously partisan, weaponising a Northern Ireland Bill for Brexit in a way which we usually, rightly, try to avoid.
“It could easily put us through all of that grief for no good reason at all if it fails to become law.”
But Shadow Brexit Secretary Sir Keir Starmer said: “For Boris Johnson to try to shut down Parliament to force through a destructive ‘no deal’ Brexit would be a constitutional outrage.
“Now it would also be unlawful. A huge victory.”
It comes hours after Boris Johnson said he would ramp up planning for No Deal after taking office.
The Tory leadership frontrunner has said he will take the UK out of the EU “do or die” on October 31, deal or no deal.
But today the government’s official spending watchdog predicted No Deal Brexit would trigger a year-long UK recession starting this winter.
In the first forecast of its kind, the Office for Budget Responsibility said a recession would begin in the final three months of 2019 if the UK leaves without agreement.
The pound would drop in value instantly by 10% – while unemployment would rise by more than a quarter.
GDP would fall 2% by the end of 2020, around the same as the early 1990s recession and a third of what was seen in the 2008 financial crisis.
In all No Deal would add about £30billion a year to government borrowing from 2021, the OBR said – or, put another way, £577million a week.
That in turn would hike the UK’s net debt by 12% of GDP by March 2024.
Despite the drastic findings, OBR forecasters said their stress test was “by no means a worst-case scenario”.