MPs who briefed against Jeremy Corbyn should ditch their grudges and “come on board,” a key supporter of the new leader told the Star last night.

Shadow cabinet members including Rachel Reeves, Tristram Hunt, Emma Reynolds and failed leadership contender Liz Kendall announced their resignations from the Labour front bench, as Mr Corbyn’s campaign announced the new team would be appointed by Monday.

But Cat Smith, a longstanding ally of Mr Corbyn who was elected to Parliament this year, said her colleagues should take a leaf out of Mr Corbyn’s book and follow “the mandate of the party.”

She said: “He’s not somebody who holds grudges and the message to my colleagues in the parliamentary party would be to graciously accept the results and come on board with the project.”

She wasn’t alone in wanting party unity. GMB’s Paul Kenny, who chairs the union-labour link Tulo, said: “There will be plenty of room for people with alternative views and arguments in the Labour Party but at the end of the day the sniping has to stop.

“Those who cannot accept the democratically elected leader of the party should ’ave it on their toes now.”

But throughout yesterday frontbenchers came forward to confirm that they would not serve under Mr Corbyn.

Shadow chancellor Chris Leslie, third-placed leadership contender Yvette Cooper and shadow business secretary Chuka Umunna also ruled themselves out.

Meanwhile the Star understands Eurosceptic MP Kelvin Hopkins, a key ally of Corbyn on Labour’s left flank, is unlikely to take a prominent role.

It is thought Mr Hopkins would prefer to campaign for EU withdrawal free from the shackles of the official party line.

Mr Corbyn’s campaign agent John McDonnell, another long-serving standard bearer for the parliamentary left, said Mr Corbyn’s team would take a different approach to opposition.

“Hopefully by Monday by the time we go to the Parliamentary Labour Party we’ll have a shadow administration in place,” he told supporters at a Westminster pub after the special leadership conference.

“And with that shadow administration, we’ll seek, not just to prevent Tory legislation, not just to prevent attacks on our communities — we want to bring this government down.”

Those tipped to become shadow chancellor include Jon Trickett, John McDonnell and Michael Meacher — but Angela Eagle is considered the favourite after her strong showing in the deputy leadership race yesterday and the election of men to both top posts.