There is confidence among Constituency Labour Parties that Sunday’s fiendishly complicated compositing process will result in a motion being put to conference on Monday that contains a phrase like "Labour must reflect the overwhelming view of its members and voters, who want to stay in the EU, and Labour will therefore campaign energetically for a public vote and to stay in the EU in that referendum".

Which is anathema to Jeremy Corbyn who wants his party to remain neutral in the coming general election between Remain and Leave.

A source close to Corbyn tells me he expects the block vote of the unions to defeat that motion on Monday when put to conference, although another source told me the two giant unions, Unison and Unite, are no longer as one and Unison may peel away from Unite and abstain.

Len McCluskey, General Secretary of Unite the Union. Credit: PA

Either way it would be beyond words extraordinary for Corbyn to rely on the union block vote to crush the revealed will of party members, given that Corbyn has spent almost half a century campaigning for power over policies and personnel to be transferred to members.

Some will see what Corbyn is doing as the great betrayal of his mentor and hero Tony Benn, who was the foremost champion in parliament of the Campaign for Labour Party Democracy.

That said, Benn hated the Common Market and EU.

So perhaps for Corbyn's euroscepticism trumps party democracy.

UPDATE Sunday 22 September - 23:10

So in the end two Brexit "composite" motions were agreed, one saying the party must come out for Remain now and the other endorsing Corbyn’s preference for ambivalence before the election.

A procedure committee is meeting now to assess if both are in accordance with party rules.

If they are, conference could do something utterly bananas and illogical tomorrow and endorse both.

It all comes down to whether the big unions, Unite, Unison and the GMB vote in a pack to support Corbyn, or whether (as I said earlier could happen) Unison rebels.

UPDATE Sunday 22 September - 23:58

Sources close to Corbyn say they still expect the big trade unions to stay loyal to Labour’s leader and vote down both motions.

However other Labour sources say Unison could well vote against Corbyn, whereas the GMB could abstain.