Isn’t this guy sort of a ‘never-was’/’has-been’ ?
(I don’t really follow Brit stuff...)
Yes; after losing big(ly) to Johnson and the Tories, he announced that he would step down as Labour leader (but not when).
He was the leader of the Labor Party. After the electoral butt-kicking his party just took, his political future is very uncertain.
He was a radical backbencher and then the British leadership election system got broken. They made it more like primaries in the US, but Brits are not used to it, only the radical people organized, turned out and elected him the leader of the Labour party.
He recently led Labour to it’s greatest electoral defeat since 1918.