What we need is more of the former UKIP vote to end up balking at the thought of voting Tory when it comes to it and either staying home, switching back to Labour or voting UKIP, but there/s no option for voting UKIP in 200 of the key seats so it's mainly down to the first 2 options.
Though some of the polling is showing a bit of a swing from UKIP to Green, presumably as an anti-establishment vote.
Looks like the Greens are going to take a battering in most places, but hopefully can do enough on a local level in a couple of places to end up with an extra MP or 2.