It is a truth not be overlooked that the Cayman Islands is a creation of the United Kingdom Parliament. So too are a score of other "Overseas Territories" which have been created for the sole purpose of allowing the wealthy to bunga bunga their money. Add to this list the Crown Dependencies of the Channel Islands and the Isle of Man, which do very well out of the tax haven status accorded them by Westminster.
There is a simple solution: incorporate all the overseas territories and the crown dependencies into the United Kingdom, subject to UK law and sending MPs to Westminster. It's what the French do with the left overs of their Empire, though of course they also tolerate Monaco and Andorra for the same reasons that we tolerate Jersey and Guernsey.
Mr Cameron and Mr Osborne would lose friends, of course, if they attempted anything so foolish as I am suggesting. What is curious is the unanimity of all of our elected representatives that money laundering, tax avoidance and tax evasion should be enabled by UK legislation. Find me an MP who is opposed to it!