Opposition leaders have joined forces to accuse Theresa May of showing contempt of Parliament.
In a highly unusual move, they have sent a joint letter to the Prime Minister expressing concern about her sudden cancellation of a crunch Commons vote on the Brexit deal that was due to be held on Tuesday.
The letter says: "We believe that this deferral shows a contempt for Parliament."
It adds: "You admitted in the House that you are running from a heavy defeat on your deal in the House of Commons.
"It cannot be right that the Government can unilaterally alter the arrangements, once this House has agreed on a timetable, without the House being given the opportunity to express its will."
A 'meaningful vote'
Watch: Prime Minister Theresa May speaking in the House of Commons on Monday.
The letter, signed by Labour's Jeremy Corbyn, SNP Westminster leader Ian Blackford, Liberal Democrat leader Sir Vince Cable, Plaid Cymru's Liz Saville Roberts and co-leader of the Greens Caroline Lucas, demanded assurances from the PM on what happens next.
The opposition leaders want to know if the Brexit deal is dead and if revised proposals will be substantially different.
They want assurances that the Commons will be given sufficient time to debate the Government's negotiating objectives.
The opposition leaders have urged the PM to allow the Commons to vote on her move to defer the Brexit deal vote, and they want to know when a "meaningful vote" on a Brexit deal will be held, and if a Government requirement to make a statement to the House on a no-deal scenario by January 21 still applies.
The Government was last week found by MPs to be in contempt of Parliament for not publishing the full Brexit legal advice. Ministers then made the advice public.