I’m just not a tribalist. I believe one should be able to be critical of all who seek power over us and fully analyse their policy, background and history. I personally find Labour seriously wanting in all areas. That does not mean I would use them as an anti-Tory tactical vote in a key marginal, but I live in a seat where an expenses-fiddling teen sex-tester and paedo-conspiracy-theorist in a red rosette could get elected, and did (now replaced by a more credible if boring replacement).
Basically I don’t need to vote Labour as it is impossible for anything else to win here. As such I can safely vote with my conscience, which is for other less authoritarian/nationalist and more democratic non-Tory alternatives. I will never get representation for my vote, but it will count on the national total. To be honest I don’t even know if there is a Green standing in May, but if not I’ll vote LD, mainly to piss you off! The Tories aren’t contenders here so it is perfectly safe!