Labour's Clive Lewis has become the first MP to call for Prime Minister Sir Keir Starmer to be replaced by Andy Burnham.
Speaking to Channel 4 on Friday night, Mr Lewis said the Labour Party must put 'country before party' and boot out Starmer in favour of the current Mayor of Greater Manchester.
The MP for Norwich South broke ranks from the rest of his party for the first time in September, when he called for the Prime Minister to stand down.
But last night he became the first to actively endorse leadership rival Mr Burnham, in a week in which a briefing to journalists put the Prime Minister in a precarious position ahead of this month's Budget.
Mr Clive said: 'We need to do what the Prime Minister once said, which is put country before party. And frankly, party before personal ambition.
'I just don't see how this can stagger on without any kind of resolution on the horizon.
'And I think the Labour party, the Labour grandees, the men in grey suits now really, seriously think, how can we get Andy Burnham back in to this parliamentary Labour Party and let him step up and become the next Prime Minister?
'That's my personal view. I know it won't be shared by everyone, but I don't see many other options.'
DM.