This is what politicians do isn't it.they unleash forces to fuel their own rise to power then get scared when they realise they can no longer control those forces, that the force has a trajectory of its own, will overshoot the ambitions of its liberator.
the problem is lump of labour is not the right way to look at this. what has happened in the UK is that unions especially have become very xenophobic and exposed for what they always were, defenders of that section of the proletariat/lower middle class who have an interest in defending capitalism. hence the huge overinflated trade union bureaucracy whilst both the labour party and unions are at an all time low of success.
in terms of the establishment remain campaign it was just as xenophobic as the leave campaign towards Indians, Africans and Muslims. what the remain campaign had was a large civil society creative base. and given many media creatives in Europe are obviously EU citizens you'd have to have this.
Corbyn's labour to this day has still not proposed to obliterate Yarls Wood.
As bad as the rise in right populism is, and as a middle easterner I always have to be on guard, I'm still not convinced it's anywhere near as bad as the 70s. That doesn't mean it isn't terrible, it is, but this seems to be overegged on by an internal leftist culture war. noone wanted to say it at the time but a lot of leftists were thinking 'what if trump won?' rather than just not backing the dems.