Labour rebels have started plotting another challenge against Jeremy Corbyn next year

Labour rebels have started plotting another challenge against Jeremy Corbyn next year, after vowing they will 'never' accept his leadership.

The hard-Left veteran is set to be confirmed as Labour's leader on Saturday for the second time in 12 months, following a bitter contest against rival Owen Smith.

Labour insiders predict Mr Corbyn could even increase the 59.5 per cent of the vote he won last year, despite losing the confidence of his MPs.

But last night there was little sign that he would be able to heal the rift with his MPs that saw 65 members of his front bench quit in the summer.

Sources close to Mr Corbyn insist that some of those who resigned will agree to return to the front bench if he is confirmed as leader today. 'Some of the names will surprise you,' a source said.

But many more have told Mr Corbyn they will never work for him again – leaving him struggling to appoint a full team to hold the Government to account at Westminster.

Labour insiders suggest that fewer than a third of the MPs who quit Mr Corbyn's team have agreed to return.

Some MPs yesterday said they were already planning another leadership challenge next year – the earliest possible opportunity under Labour's rules.

One former minister said: 'The result looks like it it's going to be disappointing, but we will just keep going until we get rid of him.

'There will be another challenge next year, and the year after that if necessary – we can never accept him because that would mean accepting Labour is finished as an electoral force. He was close to going in the summer – we will grind him down.'

Mr Corbyn's campaign manager Sam Tarry yesterday appeared to accept that today' s result is unlikely to settle the row between the leader and his MPs.

The hard-Left veteran is set to be confirmed as Labour's leader on Saturday for the second time in 12 months, following a bitter contest against rival Owen Smith

He told the Guardian: 'I think there has been a concerted effort between Owen Smith, the more hard-right MPs and relics like Neil Kinnock to say that the Labour Party will never win a general election. It sounds as if they are gearing up for round three.'

Mr Tarry said some rebels appeared to be willing to 'destroy the Labour Party just to stop Jeremy.'

But, in an ominous signal, one of Mr Corbyn's union backers yesterday said he needed to do much more to prove he can win.