Two of Jeremy Corbyn’s closest allies have piled pressure on the Labour leader to back Remain in a second Brexit referendum.
The party chief has left the door open to campaigning to quit the EU - with a deal renegotiated by a Labour government.
But today, Shadow Home Secretary Diane Abbott vowed to press for staying in the bloc - regardless of any fresh concessions won by their boss.
It comes after Shadow Chancellor John McDonnell also confirmed he would back Remain in a second referendum.
Ms Abbott told the BBC: "We are, of course, the party’s committed to a referendum now.
"And Jeremy’s (Corbyn) made that clear and if there is a referendum and if remain is on the ballot paper and there’s every expectation it will be, I - like John McDonnell - personally will be campaigning for remain.”
Mr Corbyn, who was accused of failing to campaign for Reman with any enthusiasm in the 2016 referendum, has repeatedly refused to rule out backing Leave at a referendum re-run.
Instead, Labour has suggested he - and the party as a whole - could campaign for an alternative Labour Brexit deal.
But Ms Abbott said: “The party and the Shadow Cabinet will have to debate this and arrive at a position.
"Whatever the position is Jeremy will follow what the party says."
If the Shadow Cabinet backed leaving on a Labour deal, it raises the prospect of Remainers such as Ms Abbott being forced to quit the frontbench if they wanted to fight to stay in the EU.
It comes as Boris Johnson flies to Berlin tomorrow for talks with German Chancellor Angela Merkel.
The PM’s bid to reopen the Withdrawal Agreement and scrap the Irish Backstop was earlier slapped down by Irish counterpart Leo Varadkar.
