British PM to unveil new Brexit strategy

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 crash out of the European Union on March 29 unless MPs can force a delay or come up with an alternative plan that Brussels is also happy with, before the deadline.

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

EU leaders have signalled they could alter the agreement if May dropped some of her negotiating "red lines" but British media on Monday reported that she would instead attempt to negotiate some changes to the existing agreement.

The reports were met with scepticism in Europe.

"I don't think it can be saved by marginal adjustments in the current plan. I don't think she can convince MPs by presenting the same thing to them with slight tweaks," Spanish Foreign Minister Josep Borrell said in Brussels.

"It therefore has to present something substantially different."