My quick (and probably off) analysis: Tories found this timing to be the best one to call an election based on the disarray of UKIP and Labour. Tories are again playing politics, they want to get a good slice of UKIP vote and keep Labour at the current level at best. I believe the only real alternative to another May government is for Lib Dems, Labour, Green, to make a coalition against this Tory initiative. Otherwise, should be an easy win for May.