The downturn which has wiped £155bn off the wealth of the UK superrich could lead to non-domiciled residents opting to pay tax on their overseas investments rather than the £30,000 levy which the government enforced in 2007, according to a lawyer.

The government anticipated that more than £350m would be brought into the government purse annually by the £30,000 charge. Given the global recession, this seems unlikely, according to private client law firm Boodle Hatfield.