Firstly, let us assume that many of our MPs are not corrupt. The problem is that we can't easily identify them. There is no doubt that "All power corrupts...", and that the current party political system is a failure. And this is the case irrespective of how many of our elected representatives are personally moral.
Secondly, I can see no smooth route for these parties to a responsible parliament. So we need to look for a new solution. Short of getting Guy Fawkes to do the job properly, we do have a chance at the ballot box. The problem is that voting for the opposition candidate at the next General Election will merely replace one corrupt party with another. The Labour Party is playing the radical right card, to try to scare us away from thinking of alternatives. The BNP is clearly not an alternative, and UKIP are equally 'anti-foreigner'. Fortunately the wide range of neo-fascist parties should spread the vote.
So what is the alternative? The only party that I can seriously consider voting for is the Green Party, and highly recommend their Think Again video. The fact that they are thinking in a 50 year time scale is praiseworthy - as I've said before our leaders simply failures, so could the Greens be any worse? I think not.