Jeremy Corbyn victory: Unite behind leader, Tom Watson tells Labour

Labour MPs must respect the mandate Jeremy Corbyn has been given by members, deputy leader Tom Watson says.

Few MPs backed Mr Corbyn in the leadership contest, which he won with 59% of the vote - and so far eight members of the current shadow cabinet have refused to serve under him.

Among them is shadow business secretary Chuka Umunna who said he had left the shadow cabinet by "mutual agreement".

Mr Watson has insisted there is "zero chance of a coup" against Mr Corbyn.

He said he understood it was a huge change for MPs but the new leader wanted to build a broad-based party.

'Someone else'

Mr Watson also told the BBC's Andrew Marr Show he had differences with Mr Corbyn over the leader's desire to scrap the Trident nuclear deterrent and take the UK out of Nato.

But he said his message for those refusing to serve in the shadow cabinet was "there's always someone else that can do a front bench job".

In other developments:

• Mr Corbyn, MP for Islington North, spent the morning at an annual "fun day" organised by Camden and Islington NHS Mental Health Trust

• He is expected to spend much of the rest of the day at Labour's Westminster headquarters as he finalises the shadow cabinet line-up

• Two shadow cabinet posts have already been confirmed - Rosie Winterton will continue as chief whip and Ian Murray will continue as shadow Scottish secretary

• Shadow Northern Ireland secretary Ivan Lewis has tweeted that his role has been "offered to someone else" despite telling Mr Corbyn he was willing to remain in the role

• Angela Eagle and John McDonnell are both rumoured to be in line for the key role of shadow chancellor

• Labour says 15,500 new members have joined the party in the past 24 hours

• Live updates: Follow the latest in text and video

Analysis

Mr Corbyn declined to reveal shadow cabinet names as he left his north London home

By Robin Brant, BBC political correspondent

Tom Watson made it clear this morning that he has his own "mandate" as Labour's new deputy leader to change the party - he didn't run on a joint ticket with Jeremy Corbyn.

The truth is the two men don't know each other that well. The new leader has spent most of his political career on the periphery of his party - he's not been the first port of call for consultation - which is why Tom Watson found himself admitting he's not aware of his leader's precise position on Nato.

But there's no doubt the two men are diametrically opposed on the fundamental policy issues of Britain's nuclear weapons, Nato and the EU. There's no doubt, either, that one or both will have to shift if things are going to last.

The promise of a more open and democratic party gives them time to make that happen, but it can't take long.

Defeated leadership rivals Yvette Cooper and Liz Kendall, shadow education secretary Tristram Hunt, shadow work and pensions secretary Rachel Reeves and shadow chancellor Chris Leslie, are among seven shadow cabinet resignations since Mr Corbyn's election.

Shabana Mahmood and Emma Reynolds have also quit as shadow chief secretary to the Treasury and shadow housing minister respectively.

Others, such as Andy Burnham, have not ruled themselves out.

'More complicated'

BBC political editor Laura Kuenssberg says it has been a "mind-bending" 24 hours in British politics.

She added that the process of appointing a shadow cabinet "was already going more slowly than Team Corbyn had wanted".

"An early sign, perhaps, that this whole project, even despite his huge victory, may be more complicated to deliver than they'd hoped," she added.

Yvette Cooper (R) and Liz Kendall have both said they will return to the backbenches

In an article for The Observer, Mr Corbyn said he would appoint a "unity" shadow cabinet which draws on MPs from across the party and would continue Labour's 50-50 gender split.

He also signalled he would not back British air strikes in Syria and said the government should stand up to its allies in the Middle East and oppose Saudi Arabian bombing in Yemen and Bahrain's quelling of a popular uprising by force.

Senior party figures such as Lord Mandelson and David Blunkett are among those who have warned the party risks becoming unelectable without action to temper the new leader's radical left-wing mandate.

And moderate Labour MPs have held "informal" talks about challenging Mr Corbyn when Parliament returns next week by organising a vote of no confidence, according to the Telegraph.

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The Jeremy Corbyn Story

Mr Corbyn has been on the fringes of the Labour Party in the House of Commons for the past 32 years and did not regularly attend the weekly meetings of Labour MPs.

His policy programme, which includes scrapping nuclear weapons and renationalising utilities, is a major departure from recent Labour policy.

But his anti-austerity message and authentic image attracted Labour members and supporters who voted for him in their droves.

He won on the first round of voting in the leadership contest, taking 251,417 of the 422,664 votes cast or 59.1% - against 19% for Andy Burnham, 17% for Ms Cooper and 4.5% for Liz Kendall.

Mr Watson said he wanted Labour's policy-making process given back to members, as that was the only way to reconnect to communities they had lost.

'Work it out'

But the former defence minister also suggested he had differences with Mr Corbyn.

"I need to be honest about where I stand on things," he said.

"I think Nato has kept the peace in western Europe for half a century, and Jeremy has said that - but he's also said he's worried about the eastern expansion of Nato, and I think he's right to be cautious on that front.

"But we've got to work this out, you know, I've only been deputy leader for about 20 hours."

Conservative minister Michael Gove, speaking on the Andrew Marr Show, congratulated Mr Corbyn, whom he said enjoyed a "very special sort of vindication" given the scale of his victory.

Asked if Mr Corbyn could win the 2020 general election, the justice secretary said: "Yes, and we have to face up to that reality."

Prime Minister David Cameron tweeted: "The Labour Party is now a threat to our national security, our economic security and your family's security."