I think there's a lot of assumptions going into current polling. Labour is disenfranchising a lot of people, but a large number are becoming true "don't knows" and taking themselves out of polling calculations.
These are the the left of the party who are politically homeless. The greens are mopping up some of them, but Polanski is a divisive character. Some love him, and some find him superficial. Some might land in the Lib Dems as their social policies are left of labour, but there's a lot that would never even consider that. Corbyn was trying to set up a party for them, but that's never going anywhere.
One thing is for sure, this block is not voting for Farage. He's diametrically opposite to what these people believe in.
They need to stop being an authoritarian and economically right party. People voted for change, and have not gotten what they voted for.