The true "crossover" point is at about 4+ to the Tories due to the boundary shite. And of course this is a very broad brush, assuming a uniform "swing".
This is bad for Labour, but the Cons can't be too complacent at all - they're still polling below their voteshare in 2010. But you end up in rather a similar situation to the XBone vs PS4 - sure, the XBox could come back and do very well. The PS3 managed it, after all. But in terms of predictions, if you had to guess, what reason is there to actually think it will (as opposed to keeping open the option that it might)? I can't think of anything on the horizon that Labour has to pull out of its sleeve. They can't have another Clause 4 moment, because they don't have any more unelectable goats to sacrifice. The only way I can see Labour achieving a higher vote share (As opposed to higher seat count, which I think they could limp over with, though I still think a Tory minority is more likely) is if they have a monster campaign and the Tories have a bunch of personal scandals.
Also, one of the polls recently had the Tories top of a European Parliament voting intention poll. That's a first and, I assume, an anomaly. All the rest have had them coming in third.
