all you can say if that result did come to pass would be that three and four way marginals would become the norm, tactical voting would become impossible and there would be loads of fluke winners (and Onasyana/O'Mara style flameouts in the ensuing parliament) and high profile losses from both Labour and the Tories.
Agree that it would be far worse for the Tories than Labour though, because the former would have no real safe regions to fall back on - even blue counties like Surrey would collapse.
If the above estimate of vote/seat share is true then it seems like the 8% Green vote would have considerable incentive to engage in tactical voting
