I have always voted Labour, and have often been a member of the Party, campaigning and canvassing for them. For what it’s worth, here’s my feeling about voting Labour next General Election:

 1. Every time I vote Labour after they move rightwards, they just move further right, to the point where they are now probably right of where e.g. John Major’s party was. And then the Tories then go further right still. At some point, we have got to stop feeding this endless drift by making the Labour Party realise that it’s going to cost them votes. I can’t think of anything more important that halting this constant rightward drift. So I am no longer voting Labour.

2. If a new socialist party starts up, it could easily hoover up many of the 200k former LP members who have left in disgust (I’d join), and perhaps also pick up Union affiliation. They could become the second biggest party by membership quite quickly. Our voting for that could rapidly change the political landscape in a way that would make it more reflective of public opinion (see below). I strongly support that.

3. Our voting for an alternative party that’s to the left will cost Labour votes in key marginals, and that prospect will scare them. Just as the Brexit Party was hugely influential in shaping Tory policy without winning seats, a socialist alt party could be equally effective, forcing the Labour Party to move left.

4. The Labour Party is now run by people some of whom worked against a Labour victory under Corbyn, celebrated the fact that he lost, endlessly smear thousands of decent people (like, I think, myself) as trots, thugs, antisemites (see this), homophobes, terrorist sympathisers, etc. and who would rather burn the house down that allow someone with my sort of mild leftwing (by European standards) politics get anywhere near power. Why would I vote for people who despise me, want people like me out their party, and are so hostile to the kind of policies I favour?

5. If Labour win next time, it will cement for ever the narrative that the left can never win (when in fact they achieved a hung parliament in 2017 and probably would have won with a couple more weeks of campaigning given their upward trajectory under the press moratorium,

or if their own MPs hadn’t been constantly sabotaging their party from the moment they pulled ahead in the polls, 

despite the party having policies that the public actually like:

https://www.youtube.com/watch?v=W7lsRbDKOXg

6. Kier Starmer is a habitual liar and, frankly, a backstabber who betrayed the Party membership. I don't want people like that in power. 

True, not voting Labour may be to let the Tories in again. But I think we now need to play the longer game. Currently, neither main party is likely to do anything to reverse growing inequality and privatisation, despite the fact that the public favour that. Inequality increased even under New Labour:

https://journals.openedition.org/osb/1174

For decades, realistically, our choice has been between two options: to put into Government a party that allows inequality to increase more quickly or a party that will slow the growth down a bit. But the direction of travel is always the same: growing inequality. Somehow, we need to get a party in to power that will reverse the direction of travel. Voting for Labour next time makes it significantly less likely we will ever be able to do that.