Seems to me that it's actually a little offensive for prominent members of the Labour party to discuss, ahem, "gays" the way they do. Perhaps many homosexual people have admitted to considering voting Conservative in the next general election for a raft of different reasons (eg being disatisfied with broader Labour policy, if not that directly linked to homosexuality) that aren't necessarily linked to who they sleep with. Or maybe it's because Tory policies will actually be beneficial for them in ways which are related to their lifestyle (eg less likely to be parents so won't necessarily want to subsidise family-orinetated tax schemes or have their disposable income pillaged).
The Tories are just as bad though. "We've got some gays on the team!" isn't exactly the retort I'd hope for.
My conclusion: both parties are acting incredibly stupid and probably a teeny bit homophobic for treating 'gays' as one dimensional characters.