Professor Stephen Hawking has called for Jeremy Corbyn to stand down as Labour leader, claiming he is a "disaster" for the party.

The Labour-backing physicist said he would vote for Mr Corbyn and that he approves of many of his policies but he believes he should quit "for the sake of the party".

The Cambridge University academic told The Times: "I regard Corbyn as a disaster.

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"His heart is in the right place and many of his policies are sound but he has allowed himself to be portrayed as a left-wing extremist.

"I think he should step down for the sake of the party."

Prof Hawking backed Labour's Cambridge MP Daniel Zeichner at the general election in 2015 and was pictured with him on a campaign leaflet.

At the time, Mr Zeichner said: ''I think he fully appreciates the huge investment that the last Labour government made in science and you can see that in a lot of the buildings and laboratories around Cambridge.''

Mr Zeichner, a shadow minister, did not immediately respond to a request for his response to Prof Hawking's criticism of his leader.

The acclaimed physicist's intervention is the latest sign of unease within Labour ranks after shadow chancellor John McDonnell suggested there was a "soft coup" being mounted against Mr Corbyn.

Mr McDonnell, a key ally of the leader, attempted to smooth over divisions at a meeting of the Parliamentary Labour Party on Monday night.

The shadow chancellor made a fresh plea for unity because it is "what the Tories fear most" ahead of Wednesday's Budget.

But Labour MPs Wes Streeting and Peter Kyle raised concerns with him, apparently referring to his "soft coup" claims.

Mr McDonnell's spokesman said his "element of contrition was about not just that, but over the past" as well.

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One Labour MP present at the meeting said Mr McDonnell did not apologise for claiming last week that elements in the party, in alliance with the "Murdoch media", were intent on "destroying" Mr Corbyn.

But the shadow chancellor's spokesman said: "His element of contrition was about not just that, but over the past, from the summer when he chaired Jeremy's campaign, and also since then, it was about putting most importantly and front and centre that the Labour Party is united on this front (the Budget)."