The Peer gave a blistering criticism of ex-Prime Minister Tony Blair in an interview on Wednesday, but blustered when discussing Kendal, forgetting her name and instead referring to her as "the candidate from the right".
Following the 'brain fade', reminiscent of Green Party leader Natalie Bennet's faltering performance on the same programme back in February, Prescott went on to criticise Blair for claims the left-winger and frontrunner Jeremy Corbyn would lead the party into an electoral wilderness, quipping on the ex-Prime Minister's wisdom: "He's not God-like!"
Speaking to the BBC Today programme, Prescott lamented criticism of Corbyn as needing a 'heart transplant' by Blair on Wednesday, saying: "He can't know - he can give a judgement - I can give a judgement - but at the end of the day the judgement belongs to the party, so let them decide who they want as leader.
"Personally I did support Jeremy to go on the list ... because I wanted to widen the debate, and we've certainly got a wide debate now."
The Labour Peer also took a swipe at John McTernan, a party advisor, who has been openly critical of some leadership candidates, whom he decried in an interview on Radio 4 as a "moron".
Prescott speaks to Today presenter John Humphreys
When asked if his claims about advisors advocating abuse of the nominees was a reference to McTernan, Prescott hit back, retorting: "Who the heck is John McTernan?
In a reference to the aide having led failed election campaigns both for Scottish Labour and the Australian Labor Party, Prescott added: "I mean he advised in Scotland and we lost, he advised in Australia and we lost, he wasn't in the Blair camp of any political substance whatsoever, and there he is being bought on to the broadcast speaking with some authority.
"He has no authority. Morons!"
"Let's calm down," he finished his rant with, in a manner that suggested he himself was far from it.
The Labour Peer held nothing back in a series of blistering criticisms of colleagues.
His comments came just hours after shadow home secretary Yvette Cooper played down calls for her colleague and fellow leadership competitor Liz Kendall to bow out of the race given her lacklustre performance so far, saying Kendall should not "go home and leave it to the boys just because of one poll in The Times newspaper".
Cooper added: "I do think that it's time to smash that last glass ceiling. I think it would be great to have a Labour leader and more importantly a Labour woman PM. I think we should shake up the old boys' network in Westminster.