So one interesting fact which I'm pretty sure I once knew and since forgot, is that the archaic meaning of the word "slut" was a slovenly and untidy woman, and didn't quite mean what it means today.
Not that it helps Godfrey Bloom, who should've known better, and is probably not the kind of fellow I'd care to invite for tea. Having said that, I still wouldn't vote for UKIP, but by golly they're by far the most entertaining of the lot.
(Update: and actually, Dot Wordsworth at the Spectator weighs in - both meanings are archaic and ran parallel. So there)