Its not just Labour voters, its Labour MP's, I know he is not MP but representative, seen Alistair Campbell tweet today.
"I suspect some of the young people voting Labour and voting for the first time were hoping for something a bit less Brextremist from JC/JMcD"
Meanwhile we saw Labour MP's today delightfully telling interviewers that the Tories would tear themselves apart over Brexit, ironic its going to be Labour who do exactly that!
Weird init, I told posters here if you didn't want to leave the Single Market then the LibDems was the only game in town and they invested all their time and effort in defending Corbyn.
A last gasp LibDem - Tory coalition could save the day for remainers and get a referendum on a deal in the Queens speech, yet they are deluding themselves they won when in fact they lost.
The establishment wants you to think there will be another general election soon and can change all this, dream on.
The DUP will do a deal Tuesday, after that any hopes of membership of the single market/EU is possible is over.
I don't think the Tories will do the deal with the LibDems although that would certainly relieve pressure on the DUP front.
Secondly Brexit since there are factors out of the control is a negotiation and not exclusively a manifesto commitment.
Corbyn can afford to shit his support off on this one but of course will ultimately pay.
I think we need to look at this question as an equivalent of say ''matching spending for the first period of government''. The getout will be that it is a Jobs Brexit, the groundswell when voters became more aware was that this was only possible if (fill in gap).
On the other hand it could be that they were caught out by May's announcement that an agreement was on the cards. After all May had been to the Queen. In the event of that the manifesto of labour would have been defeated anyway and a new one will have to appear at the nexr election.
Technically then Labour are not bound to any manifesto commitment.
More importantly though if May has Duped her Madge and the GBP about the status of her deal then that must be a serious constitutional issue.
My guess is that Corbyn knows May is going to be able to make that speech and carry on.
I can't see how Labour though can be as unflexible as you suggest in negotiation and willing to crash out.
Campbell is always Good value but is not the man on the ground as party senior leaders in an omnifuckup not of there own making as Mc Donnell and Corbyn are and where political guile and cunning are necessary.