Jeremy Corbyn has been warned by a veteran leftwing MP he will have to quit as Labour leader if he becomes a "liability" like Gordon Brown, Ed Miliband or Michael Foot.
Paul Flynn, a friend of Corbyn who sits on the same wing of the party, said on Friday it was not sustainable for the leader to be at war with his shadow cabinet.
Labour has been engulfed in a row over whether or not to vote in favour of David Cameron's bid to launch airstrikes against Isis in Syria. Corbyn is opposed. But the majority of his shadow cabinet want to vote with the prime minister.
Two Labour MPs today said they thought it would be better if Corbyn resigned as leader - despite only being in post for two months.
Flynn told BBC Radio 4's World at One programme this afternoon: "There are terrible divisions in the party there is a gulf between the leader and the shadow cabinet, between the PLP an the party in the country. It's a terrible, terrible mess and it can’t go on.
"I said to Jeremy: 'If you end up like Michael Foot and Gordon Brown and Miliband as a liability to the party, if you are far less popular than the party coming up to an election, then you’ve got to go'.
But Flynn warned Labour MPs not to try and oust Corbyn. "The only way he can go is if he decides himself to go because he is there with a huge majority from the party in the country and if the PLP attempt to throw him out there would be a terrible rift in the party also possibly a split in the party."
The veteran MP added that it was not sustainable for the shadow cabinet to be at war with its own leader. "Something has got to go," he said.
Despite sharing many of Corbyn's views, Flynn did not vote for him in the leadership contest as he said he thought the public were not left wing enough to elect him prime minister. "It's futile being ideologically perfect but politically impotent. We can change the leader: we cannot change the electorate," he said at the time.