The Blairites sabotaged the previous election campaign and they have been doing the same to this one (on a quieter scale because of brexit). They have failed to date through a combination of lack of support in the LP and through their own sheer incompetence.
If there was a Blairite/LibDem/SNP majority you would find the Blairites jumping very quickly after the election to impose Remain - but there won't be so they are stuck between a rock and a hard place.
The mistake Corbyn made was not forcing through mandatory reselection of MPs - that would have had the lot of them running for the hills.
It’s always someone else’s fault with Labour, the public don’t like Jezza/majority of the shadow cabinet and don’t want him as PM
If someone else was in charge they would be cruising this election.