Britain's opposition leader Jeremy Corbyn vowed to fight to retain control of his Labour party on Monday after almost all his policy team withdrew their support for him in protest after Britons voted to leave the European Union.

Corbyn is resisting pressure to quit over what critics say was his lacklustre effort to keep Britain inside the European Union.

They also say he has failed to demonstrate that he can win over enough voters to secure power at a national election, with a snap vote a realistic prospect after David Cameron's resignation as prime minister to make way for a pro-Brexit government by October.

"Stop the whispering, stop the corridor coups, stop trying to pressure an elected leader of the Labour Party to stand down without any vote or democracy," Corbyn's spokesman said after a stormy meeting between the leader and his party in parliament.

Corbyn's advisers reiterated his intention to stand for re-election in any leadership contest that his rivals might call.

Despite his defiance, the stream of resignations throughout the day offered a brutal critique of Corbyn's leadership: his business policy chief said the leader was partly to blame for last week's referendum vote to leave the EU.

"Too many of our supporters were taken in by right-wing arguments and I believe this happened, in part, because under your leadership the case to remain in the EU was made with half-hearted ambivalence rather than full-throated clarity," shadow business secretary Angela Eagle wrote in a resignation letter that she later posted on Twitter.

Eagle was one of at least 18 members of parliament to quit the shadow ministerial team in the space of two days.

Corbyn announced a number of appointments to replace those who had quit on Sunday, promoting several members of his inner core of left-wingers to senior defence and foreign policy roles.

Corbyn was elected party leader last year on a surprise wave of grassroots enthusiasm for his left-wing agenda and promise of a new approach to politics. But his relationship with Labour's elected lawmakers has always been fragile, with many questioning whether the party could win an election on such a ticket.

The meeting in parliament on Monday evening discussed a motion of no confidence in Corbyn, which was submitted hours after the referendum result on Friday.

The motion is due to be voted on at a secret ballot on Tuesday, although it is not enough on its own to trigger a leadership contest - something that requires 51 lawmakers to nominate a rival candidate.

Amid the drama inside parliament, more than 1,000 Corbyn supporters gathered outside the building for a noisy rally against what some of his supporters described as a right-wing coup against him.-Reuters