Newly re-elected British Labour leader Jeremy Corbyn repeated calls for unity on Sunday in his deeply divided party, but risked antagonising MPs who had opposed him by promising more power to his grassroots supporters.

Corbyn was confirmed in his position on Saturday with 61.8 per cent of the vote among party members and supporters, seeing off a challenger backed by the majority of his lawmakers, who believe he can never lead them into government.

But the main opposition party remains bitterly split between left-wingers and moderates, at a time of major change in Britain as Prime Minister Theresa May’s Conservative government negotiates the country’s withdrawal from the European Union.

In his acceptance speech at the party conference in Liverpool, northwest England, Corbyn pledged to "wipe the slate clean" after accusations of bullying and fears of an irreparable breach in the century-old movement.

The 67-year-old said on Sunday he was "reaching out" to his critics — but his proposal to give more decision-making power to party members risks being seen as an attempt to sideline MPs.

"What I want is more power for members, more power for supporters, in order to ensure we get policies that do have support throughout the whole party," he told BBC television.

"There’s a lot of thirst for change out there, people want to see things done differently." 

Labour’s membership has soared since Corbyn first became leader last September, and now stands at around 600,000. His victory over challenger Owen Smith was driven by the new members, exit poll data shows.

Many moderate MPs publicly accepted Corbyn’s re-election and backed his call for unity, but the anonymous briefings against him continued in the Sunday newspapers.

In a sign of the entrenched divisions, Labour peer Lord Parry Mitchell resigned from the party saying that it was a "lost cause" under its current leadership.

He blamed Corbyn for being "lukewarm" about tackling anti- Semitism in the party and condemned his left-wing supporters.

"Jeremy has no leadership qualities whatsoever — his little group like him and they think he’s the Messiah, but he will never become the leader and prime minister of this country," he told the BBC.