Unions force Corbyn to back remaining in EU, writes Robert Peston

Big trade unions having now agreed a joint policy of an EU referendum in all circumstances and Labour campaigning to stay in the EU.

I now expect Labour to officially adopt that position on Wednesday.

"We’ll see what happens," said one influential member of the shadow cabine, with a twinkle.

Another said: "It will be a useful distraction from the horror show of the [Labour and antisemitism] Panorama," referring to the BBC investigation into the party.

Labour is expected to formally adopt the position later this week. Credit: PA

So whether for reasons of cynical pragmatism or pro-EU principle, Jeremy Corbyn’s Labour looks belatedly set to become the referendum-and-remain party.

And goodness only knows whether it is too late for Labour to stem the Lib Dem and Green surges.

  • Update 19:30

The big unions have conceded that if Brexit happens under a Tory government, Labour would campaign to remain in the EU.

So those who want a referendum, especially People's Vote, will be thrilled.

But the unions' "scenario two", as revealed by Huffington Post's Paul Waugh, contains the mother of all internal contradictions and may be seen as the shortest political suicide note in history.

It says that if there were a general election before Brexit - which is highly likely - Labour would campaign to negotiate a deal to leave the EU that reflects its "priorities" and that it would put this deal to the British people in a referendum.

But Labour would reserve its position on whether the party itself would formally back its own version of Brexit in the referendum or would campaign to remain in the EU.

Even to contemplate the idea of a government painstakingly negotiating a revised plan to quit the EU and then campaigning against its own deal in a referendum is to soar to new heights of political absurdity.

The Lib Dems and Greens will wonder if the trade unions wish to consign Labour to the wasteland of permanent opposition or whether they have devised a cunning plan so clever as to be devastating in its incomprehensibility.

On the face of it, however, the unions appears to be inviting all committed remainers to desert Labour in a general election and go Green or Lib Dem.

All a bit odd, as I am won't to say with alarming regularity when reporting on both major parties.