I'm reminded of a story I should have covered. The Times seems pretty sure an offshore tax amnesty for UK taxpayers is coming up. See this.
In principle I don't like amnesties. I think they're unfair to honest taxpayers. But if targeted correctly - and in this case full cooperation from the banks is essential, then they can work as the Irish have shown when trail blazing in this area. So I'll buy it on a condition - that if a person re-offends or fails to make full disclsoure the penalties must be very high indeed.
I'd add another condition too. It should be mandatory that the banks supply data on offshore account holders thereafter.
Of course it won't catch everything - but closing down offshore banking within the UK bank clearing system which can happen now will be an enormous gain.