The International Commission of Labour’s National Policy Forum - which consists of MPs, trade unionists, MEPs, and constituency representatives - has voted unanimously that Labour’s manifesto for European elections should pledge to hold a confirmatory referendum on any Brexit deal.

My sources say there were no dissenting voices. On Wednesday all Labour MEPs voted in precisely the same unanimous way, for a referendum.

Friday's Labour’s Trade Union Liaison Organisation is likely to inform the party’s ruling NEC that its big union supporters - including Unison, the GMB and USDAW, but obviously not Unite - also want a referendum.

So it is increasingly hard to see how Labour’s ruling NEC can at its emergency meeting next Tuesday ignore such widespread membership pressure and do anything but adopt a confirmatory referendum as the foundation of its manifesto.

That said many senior Labour figures tell me they worry Seumas Milne and Jeremy Corbyn will somehow find a way to prevent the party adopting an unambiguous pledge to campaign for a referendum.

As one senior Labour said to me: “it is a test of whether Jeremy really believes in party democracy”.

6.40pm update

Now if you want a sense of why the NEC referendum vote on Tuesday is anything but a done deal, see this text from a Labour media official: “Just a couple of things about your tweet re the International Commission. I have it from 4 people in the room that there was no vote and no unanimity on confirmatory referendum”.

Which I thought was odd, given what my own sources from the room told me. So I went back to them and they agreed there was no vote, because there was no need for one - in that everyone in the room was asked to speak to Keir Starmer’s proposal that any government Brexit deal should be subject to ratification in a referendum and no one dissented from that proposal, although one person expressed reservations while ultimately endorsing the plan. In that sense it was passed “nem con”.

Though what matters of course is that the leaders’s office wish to downplay the significance of what the international commission of the party’s policy forum decided.