Non-domiciled taxpayers were said to be on the brink of leaving the UK this week over the government’s crackdown.

Advisers told Accountancy Age that a key aspect of their concerns is the fear that however bad government proposals are at present, they could become worse.

In a discussion paper on plans to levy a £30,000 charge on non-doms who wanted to keep off-shore income tax free, released in December, the Treasury said the rules would be open to review, a move advisers believe allows for tougher reforms in the future.

‘There is a serious concern that what we are getting is just stage one. The suspicion is that the levy will go up in time and that the rules will become tougher,’ said PricewaterhouseCoopers tax partner John Whiting.

Non-dom taxpayers in the House of Lords, such as Labour donor Lord Paul, have also come under pressure this week.

A bill proposed by Lord Oakeshott and due shortly after this week’s recess, will require all peers to be domiciled in the UK for tax purposes.