The whips’ office is receiving “dozens of phone calls”, The Independent understands – reflecting the “almost unanimous” support amongst rank-and-file MPs for a Final Say vote to come first.
Emily Thornberry, the shadow foreign secretary, became the latest big-hitter to argue for a referendum, joining Tom Watson, the deputy leader and – privately – shadow chancellor John McDonnell and Keir Starmer, the Brexit spokesman.
However, Mr Corbyn is standing firm, using a major speech to claim he is “champing at the bit” for an election – as soon as the threat of a no-deal Brexit has been lifted.
Speaking on the BBC, Ms Thornberry said: “My concern about if we had a general election is it would be a kind of quasi-referendum, that it would be all about in or out, what kind of deal.
“So to a certain extent I can see the sense in trying to have a referendum first. But it’s really just a question of how can we do that in practice.”
Owen Smith, the former Labour leadership contender, went further, telling The Independent: “It would be the height of folly for Labour to agree to an election before Brexit is resolved
“It would let Boris Johnson off the hook he has hung himself on and allow him to play the martyr in a contest that would only really focus on Brexit.
“All the polling suggests Labour would lose badly in such election, so why on earth would we dance to Johnson’s tune and risk letting down the people who need to a progressive government in Westminster?”
Another Labour MP said: “Dozens of Labour MPs are phoning the whips to say they believe a second referendum should be held first. It is the almost unanimous view.
“I assume that is the message being passed onto the leadership and, of course, Keir Starmer and John McDonnell – someone who is close to Jeremy – think the same way
“At the very least, Jeremy has got to take that into consideration before he forces us into a vote for an election that will split the party.”
However, it is still unclear how a Final Say referendum could be delivered, even if Labour explicitly backs it.
It would require Mr Johnson to be toppled in a vote of no confidence and replaced by a so-called “government of national unity” to pass the necessary legislation.
However, those cross-party talks collapsed over the failure to identify a caretaker prime minister – with Labour insisting it must be Mr Corbyn, while the Liberal Democrats and sacked former Tories say he is unacceptable.
Speaking in Northampton, the Labour leader told the prime minister: “Take no deal off the table and then let’s have the election,” promising a referendum would follow if Labour won.