Parliamentarians should declare offshore interests
. . . information of any pecuniary interest or other material benefit which a Member receives which might reasonably be thought by others to influence his or her actions, speeches or votes in Parliament, or actions taken in the capacity of a Member of Parliament.
As Dan points out:
If we are to love and trust our elected representatives again - and how we long to do so - then it is necessary for us to know whether they have assets parked offshore, regardless of their provenance. Reasonable people can disagree as to whether the use of offshore facilities is consistent with working as a representative of the British people, but we must be able to go about our business secure in the knowledge that our MPs are not being bribed by shadowy business interests.
Now that would really stir things up for the trust fund boys (and girls) in parliament.