Will Labour make manifesto promise to hold EU referendum after election?

The most important statement by Jeremy Corbyn in today’s Sunday Mirror interview is not that Labour’s leader will embrace a so-called People’s Vote if that were what Labour’s conference backs this week.

It is that Labour is “not happy” with the PM’s Chequers Brexit plan “and we would vote against it”.

This is Labour‘s strongest, least ambiguous attack on Chequers. And - as if that were needed - it underwrites the view of many Tory MPs and ministers that the PM’s attempt to sell Chequers to Brussels is even more fatuous than dead-horse flogging, given that some 50 odd True Brexit Conservative backbenchers are adamant that they would vote against it.

The Labour leader visited food banks near Anfield in Liverpool at the start of his visit to the city. Credit: PA

Which raises the stakes AGAIN for Monday’s Cabinet meeting - at which the PM faces a hugely difficult decision whether to buckle to the Brexiter pressure and shift from Chequers to the more orthodox free trade proposal wanted by her erstwhile Brexit secretary Davis and former foreign secretary Johnson (both of whom will support an Institute of Economic Affairs iteration of the Canada-style free trade deal at lunchtime on Monday).

If at the end of the year whatever she puts to Parliament in a “meaningful” vote on the terms of our withdrawal and future relationship is voted down by MPs, then it does really matter what Labour votes this week in relation to a referendum.

For what it’s worth, official sources close to Corbyn say Labour would always support a referendum rather than see the UK leave the EU in a chaotic fashion without a deal.

Jeremy Corbyn and Dawn Butler kicked off the conference weekend with speeches at a women's conference. Credit: PA

But for the referendum to happen the party may need to do more than vote this week for keeping open the option of a People’s Vote - which right now seems to be where the party is heading.

It probably needs to signal that this is the option it prefers rather than a "soft" Norway-style Brexit, since the Remainer Tories who have given up on May are currently split on whether they want a plebiscite or the softest of Brexits.

Later today Labour hacks will formulate the composite motion on Brexit that will go for debate on conference floor.

My sources say there is no doubt the motion will signal that the option of a referendum is a live and practical one for Labour.

But there is wrangling about whether the motion should include a manifesto promise to put any Brexit deal to voters after a general election.

This may seem bizarrely academic, since the probability of an early general election is less than that of a plebiscite.

But saying that Labour would commit to a vote in a manifesto would have MASSIVE symbolic power.