We all know the Labour Government is awful. But are you so naive you are prepared to risk the alternative?
George Osborne has already said that when the Conservatives are elected (although I believe he said "if" to avoid the appearance of over-confidence), they will respond to the renewed vigour of the unions by strengthening anti-union ligeislation.
Of course, that won't bother the majority, because they're not in unions anyway. They haven't got enough money to pay for union subscriptions; and the bosses wouldn't like it.
Plus those unions are only in it for themselves, really.