Well that's interesting.
https://www.theguardian.com/politics/2017/apr/18/theresa-may-uk-general-election-8-june
The Tory Gov needs a 2/3 majority to swing this under the Fixed Term Parliaments Act.
My first reaction is that Labour should refuse this and hold the Tory feet to the fire for longer.
And the second reaction is that all the current opposition parties should unite on an Anti-Brexit platform. This election is about Brexit, so let's make it about Brexit.
A cynic might assume this announcement has something to do with a couple of dozen Tory MPs being investigated for election fraud, and the Tories potentially facing the impending loss of their narrow majority.
Or maybe Theresa is looking for a escape-chute from Brexit? Could have done this a bit earlier though, eh?