UKIP members and MEPs are mostly made up of a bunch of right wing ex-Tory old men. And they are as embrollied in the expenses scandal as much (if not more so) as the Tory and Labour MPs. If you want to vote for a party unscarred by expense scandals, then vote Green on June 4th.
But UKIP could hold the key to electoral reform. It was the rise of the New Zealand Party - a party to the right of the centre-right Nationalists in New Zealand that finally brought a referendum on electoral reform over there.
Established parties to the left of the Labour party help the Tories in this electoral system, but UKIP does the Tories the most damage. If UKIP could keep in double figures then a hung parliament would be much more of a prospect.
Labour have been too frightened to take on the Tories over electoral reform, so easy places like Scotland and Wales where the Tories are a minor party and helped most by PR, were a good place to start to win Tory support for reform. Tory voters have been reinvigorated in these places as their votes now count and a lot of them now support PR there.
So all you disenchanted Tory voters, if you really want to punish the Tories but still vote against the EU then vote UKIP on June 4th. Of course UKIP are not exactly clean on the expenses issue either, in which case voting Green on June 4th is the best option.