Prime Minister Theresa May yesterday warned that parliament's rejection of her Brexit deal could leave Britain in the European Union and bring the opposition Labour Party to power.
The embattled leader's message came with her government fearing a heavy defeat tomorrow of the draft withdrawal agreement she signed with Brussels last month.
Media reports said May is under pressure from her cabinet to delay the vote and fly to Brussels to secure more concessions ahead of a planned summit with 27 fellow EU leaders on Thursday and Friday.
But Brexit Secretary Stephen Barclay told the BBC: "The vote is going ahead."
May is facing her biggest crisis since coming to power a month after the nation voted by a 52-48 margin in June 2016 to leave the world's largest single market after 46 years.
Her comments on Sunday are aimed at tamping down the hardline Conservative Party revolt led by the likes of her former foreign minister Boris Johnson.
But Johnson used a column in the Sun yesterday to argue that "the best way to get a great deal is to prepare for no deal" by rejecting May's draft.
The European Court of Justice could inject still more drama into the Brexit endgame when it rules today whether Britain can unilaterally halt its split from the bloc. The ECJ could also decide Brexit can only be postponed or suspended by unanimous agreement of the other 27 nations.
May has rejected the idea of putting the brakes on Brexit.