A vote of confidence will take place in the House of Commons tomorrow, after Theresa May's Brexit deal was rejected.
Labour leader Jeremy Corbyn tabled the vote of confidence after describing tonight's (Tuesday) defeat for the Prime Minister's EU withdrawal plan as "catastrophic".
He said: "The result of tonight's vote is the greatest defeat for a Government since the 1920s in this House. This is a catastrophic defeat for this Government.
"After two years of failed negotiations the House of Commons has delivered its verdict on her Brexit deal and that verdict is absolutely decisive."
Mr Corbyn added: "The most important issue facing us is that the Government has lost the confidence of this House and this country.
"I therefore inform you I have now tabled a motion of no confidence in this Government."
The 230-vote margin of defeat tonight was the worst suffered by any Government in a meaningful division since at least the First World War.
Mrs May now has until January 21 to set out a Plan B - expected to involve going back to Brussels to seek further concessions - ahead of the scheduled date of Brexit in just 73 days' time on March 29 .
She told MPs that the Government would "make a statement about the way forward and table an amendable motion" by Monday January 21.
She also offered assurances to the Commons that Government was not seeking to "run down the clock".
Mrs May said: "I've always believed that the best way forward is to leave in an orderly way with a good deal and have devoted much of the last two years negotiating such a deal."
She added: "Every day that passes without this issue being resolved means more uncertainty, more bitterness and more rancour. The Government has heard what the House has said tonight, but I ask members on all sides of the House to listen to the British people who want this issue settled and to work with the Government to do just that."