Labour members planning to vote for Jeremy Corbyn are doing so because they have been traumatised by their party’s election defeat, one of his rivals has said.

During a hustings on LBC Radio it was put to the leadership candidates that Mr Corbyn was leading in the polls because the other three candidates appeared incapable of giving a straight answer to “simple questions”.

However Liz Kendall disagreed and suggested that Labour members' judgement could be clouded by defeat.

“I don’t think that’s the reason why Jeremy is ahead in the poll. I think that we have been through a huge trauma as a party in the defeat," she said.

She insisted that the values she represented were actually preferred by Labour voters over those of Mr Corbyn, characterising his approach as a politics of “protest”.

Jeremy Corbyn, the surprise frontrunner for next Labour leader (Getty)

“People want in their leader somebody who is going to be able to apply our values to the world as it is; be a credible government and not take us back to being an unelectable party of protest.”

Ms Kendall is currently in last place with 11 per cent of first preference votes, according to the first poll of the contest.

Mr Corbyn was in first place with 43 per cent of votes, Andy Burnham was in second place with 26, and Yvette Cooper was in third on 20 per cent, according to the YouGov poll for the Times newspaper.

In the final round of voting Mr Corbyn would beat Mr Burnham by 53 per cent to 47 per cent.

Though polling such contests is difficult and the survey may not be an entirely accurate picture of the results, the figures do suggest that Mr Corbyn is doing very well.

Ms Kendall's assessment of Labour members comes as party figures warn against what they called a "constant stream of abuse" against members considering voting for Mr Corbyn.

“Instead of lecturing and being abusive as some advisors and commentators have done, their time would be better spent promoting the ideas and vision of their preferred candidates," East London MP Rushanara Ali said.

“The membership and registered supporters will decide our next leader. I wouldn’t be surprised if they are tired of the constant stream of abuse from people who have a track record of control freakery, stifling debate, and believing they know best.”

Former deputy prime minister John Prescott offered his opinion on the Today programme on Thursday morning.

“Candidates should now move into the areas of policies, and that’s why Jeremy’s doing so well, they know where he stands," he said, adding that "abuse" of Mr Corbyn's supporters should stop.