@ Mark
"Last time I checked British politics, you voted for a party - not its leader"
Er.. NO.
<rant>
In Good old Blighty, you vote for a CANDIDATE to represent you.
They just happen to be a member of a Political Party.
You can, of course, just vote for the candidate from the party you dislike least, or you could engage your brain occasionally prior to voting and actually vote for someone who believes in at least the same things as you do, and is possibly more likely to actually represent YOU as opposed to the Party.
If it weren't for 'party politics', then there'd have to be a whole load more cooperation between MP's, as opposed to just toeing the 'party line' in order to get put forward as candidates next time round, which is how the majority of 'career politicians' behave, as the real world would just chew them up and spit them out.
Of course, in my little utopian fantasyland, ALL MP's would be decent, honest, upstanding people, as opposed to the self-serving, expense-troughing, mealy-mouthed charlatans that a large proportion of our "Elected Members" actually are.
If MP's were prohibited from earning ANY INCOME from 'outside interests', then that should eliminate most 'conflict of interests', and weed out the ones who are just in it for the money.
</rant>
It wasn't supposed to be a rant, it just turned out that way. It's politics, after all!