The Observer reported this weekend that:
Of the £188m raised by political parties from donations since 2001, some £17.5m, or 9.3 per cent, comes from those who have declared themselves to be non-domicile or are very likely to enjoy that status. Labour has received £8.9m from non-doms or suspected non-doms. The Tories have received £5.6m.
The answer is simple: as I suggested during the Hecklers programme I did recently, if you don't pay full UK tax you should have no right to participate in the democratic process here.
I'd go further though - I'd make UK tax payable by all UK citizens whether or not resident here. This is the US system. It doesn't seem to have harmed them.