More than half of the wealthiest people in Britain are planning to leave or scale back their UK investments in response to the tax crackdown on "non-domiciled" foreigners, according to a survey.

Switzerland has emerged as by far the most popular destination for wealthy individuals leaving Britain, according to the poll of advisers representing about 22,000 non-domiciled clients.

The findings will be used in a last-ditch effort by tax planners to persuade the Treasury to rethink its plans. From April, foreigners living in Britain for more than seven years will pay £30,000 if they wish to keep their foreign income out of the British tax net. Wealthy individuals will be particularly affected by the closure of loopholes that allowed them to escape capital tax on UK assets held in offshore trusts.