The way Jeremy Corbyn was elected Labour leader was 'bizarre, peculiar and unnacceptable' says Lord Warner

Comments made despite Jeremy Corbyn being elected with 60 per cent of the vote, a bigger margin than Tony Blair was elected leader in 1994

Membership of the Labour party has rocketed by 60,000 since Jeremy Corbyn's election as leader

The way Jeremy Corbyn won the Labour leadership election was "bizarre, peculiar and unacceptable," according to the peer who has resigned the Labour whip.

Lord Warner's comments come despite the new Labour leader winning 59.5 per cent of all those eligible to vote in the leadership contest - a bigger margin of victory than Tony Blair achieved in 1994.

Membership has rocketed by more than 60,000 since Mr Corbyn was elected leader, the Labour party says but Lord Warner said he was leaving the party because it was no “a credible party of government-in-waiting”.

Lord Warner, who served as a health minister under Mr Blair from 2003 to 2007, accused Mr Corbyn's allies of “trying to get their hands on the control levers” to force moderate MPs to change their positions or face the threat of deselection.

He urged the party to make a "stand" by re-examinating the direction it was heading in under the leadership of Mr Corbyn and his shadow chancellor John McDonnell. "The Labour Party now faces an existential threat. If it doesn't change itself very rapidly indeed it hasn't a hope in hell of winning the election in 2020 or indeed in 2025," he told the BBC.

He criticised the way the party ran the leadership contest, saying it was strange that it allowed people to sign up for a vote after it announced the date of the election result.

"The process by which that election, which secured him leadership took place was bizarre," he told the BBC. "There are very few elections that take place on the basis that you name the date for election and you allow people to carry on being qualifying themselves to vote in that election right up to the day of the election of itself."

The Labour party played down the significance of his resignation and Lord Warner's fellow peer Lord Prescott described his departure as "no great loss".

In his resignation letter he wrote: “I shall not be joining any other political parties and will continue to argue for what I regard as progressive causes in both the Lords and in public. These are unlikely to be those you and your kindred spirits espouse.

“I have watched for some time the declining quality of the Labour Party's leadership but had not expected the calamitous decline achieved in 2015.

“The approach of those around you and your own approach and policies is highly likely to worsen the decline in the Labour Party's credibility.”

Graham Jones, a Labour MP, said it was “sad that Lord Warner says he’s leaving the party”. “With a policy review approaching [it is] important to shape the arguments,” he tweeted.

Another Labour MP, John Spellar, however simply tweeted: “He was always an arse.”