SUNDAY TIMES WEB DESK: With less than three months before Britain is due to quit the EU, parliament began a five-day battle over May’s Brexit plan with a show of force – undermining her preferred timetable if members of parliament vote down her blueprint next Tuesday.

May has so far refused to retreat from her unpopular deal, which envisages close trading ties with the EU, but without any say on policy as Britain has now, after leaving in March. Instead, she has pressed ahead with a vote she looks set to lose after failing to win over her nominal Northern Irish allies.

Losing the vote would deepen the uncertainty over the future of Brexit, Britain’s biggest shift in foreign and trade policy for more than 40 years, and open the way for several different outcomes, ranging from a disorderly exit to another referendum.

MPs voted 308-297 on Wednesday in favour of demanding the government come up with an alternative plan within three working days after the Jan. 15 vote, rather than a planned 21-day limit.

There were turbulent scenes in parliament when some in May’s Conservative Party accused the speaker of bias.

Responding to the vote, Brexit minister Stephen Barclay told parliament it was the government’s intention to act quickly if May’s Brexit plan was rejected on Tuesday.

“I also want to reassure colleagues that whatever the outcome of this debate, we will respond rapidly, recognising that we must provide parliament with as much security as possible,” Barclay said.

But, combined with a vote late on Tuesday when the government lost on the finance bill, the defeats underline May’s precarious position in parliament.

The opposition Labour Party said it will call for a vote of no confidence in the government if May loses on Jan. 15. One of Labour’s top policy team said this would take place immediately, but a spokesman said the timing would be decided as events unfold.