Brexit Plan B: What's next for Britain as UK lawmakers reject May's deal

British Prime Minister Theresa May unveils her Brexit "Plan B" to parliament on Monday after MPs shredded her EU divorce deal, deepening the political gridlock 10 weeks from departure day.

Britain will leave the European Union on March 29 without a deal unless MPs can force a delay or get their act together in time and come up with an alternative plan that Brussels is also happy with.

The world's fifth-biggest economy could lose preferential access to its largest export market overnight, affecting every sector, leading to rising costs and disruption at British ports.

London and Brussels have spent the best part of two years working on a divorce agreement but MPs in parliament's lower House of Commons comprehensively rejected it on Tuesday.

May's government then survived a confidence vote on Wednesday and set about talks with figures from rival parties.

But the main opposition leader Jeremy Corbyn stayed away, saying a "no-deal" departure must be ruled out first -- something May says is impossible.

May spoke to Dutch Prime Minister Mark Rutte and German Chancellor Angela Merkel on Thursday, and to EU leaders Jean-Claude Juncker and Donald Tusk by telephone Friday to discuss where to go next on Brexit.

EU chiefs have so far ruled out renegotiating the agreement, but have signalled they could postpone the withdrawal if May changes her "red lines" on leaving the EU's customs union and blocking free movement of citizens.