LABOUR is set this week to push for a new EU referendum when the UK Government brings forward its Brexit legislation to the Commons.
And Sir Keir Starmer left open the possibility the Opposition could back Boris Johnson's deal if a new national poll were attached to it.
The Shadow Brexit Secretary insisted any agreement approved by the UK Parliament had to be put to voters in a referendum and that his party would back an amendment calling for one.
He claimed the Prime Minister's deal had a "trap door to no-deal" contained within it and that Labour would, among other things, also be pushing for a customs union.
Sir Keir’s proposal on a Peoples' Vote goes much further than Jeremy Corbyn has to date; the Labour leader has previously said his party could not vote for the Johnson Plan even if it had a second referendum attached.
But some within Labour believe staging a People’s Vote is the “key priority”.
During the Saturday Commons vote an amendment for a second referendum was tabled by Labour backbenchers Peter Kyle and Phil Wilson but was not put to a vote. This is now set to be revived among a flurry of amendments being table to the Government’s new Withdrawal Bill in the coming days.
One Labour source told The Herald that Mr Corbyn was “increasingly of the view” that a People’s Vote with the Remain option included should come before an election.
Sir Keir told BBC1's Andrew Marr Show: "We need an amendment to say that whatever deal gets through, it should be subject to a referendum.
"We have already voted three times as a party for a second referendum with a three-line whip behind it. The position we have adopted is whatever the outcome, whether it's Boris Johnson's bad deal or a better one which could be secured, it has got to go to a referendum up against remain."
Asked if Labour could back the Government's deal if it came with the pledge of a new referendum, Sir Keir replied: "We'll see what that looks like.
"What we are trying to achieve is that this deal in particular but[also] any deal is put up against Remain in a referendum. We will have to see tactically how we get there."
In response, Dominic Raab described the Labour move as “extraordinary”. The Foreign Secretary said: “People are saying get this done and move on.”
But Scottish Labour MP Ian Murray, speaking on Sunday Politics Scotland, stressed how a second referendum had "always been the compromise we've been putting forward".
The Edinburgh South MP also noted how the SNP had “gone slightly cold on a People's Vote” but added, given what it had said in the past, it would support an amendment calling for one.
Meanwhile, Sammy Wilson for the DUP suggested his party would not back tagging a second poll onto the Government’s Brexit deal.
"The DUP does not seek a second referendum, merely implementation of the first," declared the Antrim MP.