The Treasury's own models indicate that 69% of those affected by the new 50% tax rate will try to use avoidance or evasion measures to avoid it.
Labour was heavily criticised in the weekend press for targeting those earning more than £150,000, amid concerns that it could drive entrepreneurial talent and high earners out of the UK.
According to the FT, people will take to relocating to areas such as Guernsey and Ireland to 'rearrange their financial affairs' and avoid paying the higher tax rate.
Jon Moulton, chairman of private equity firm Alchemy, said that the high tax rate will affect businesses at a time when they need support and that 'the move is likely to raise only a small amount of extra revenue'.
Meanwhile, Tory and shadow chancellor George Osborne said the Treasury should reveal any data and estimates regarding the issues of tax evasion with the new tax measures as 'we already know it was a dishonest Budget but it looks like it was even more dishonest than we thought'.
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