Taxes will be higher than for financial workers living in the other key centres of New York, Paris, Frankfurt, Geneva, Zurich, Dubai and Hong Kong, KPMG calculated.

The findings will raise fears that Labour’s levies are driving businesses and bankers overseas and threatening Britain’s competitiveness.

Terry Smith, chief executive of broker Tullett Prebon, warned yesterday that increasing taxes on workers and companies would only hinder the economic recovery.
‘The UK economy is an utter disaster on any number of fronts,’ Mr Smith said.

Tullett announced last December that it will help employees move abroad if they want to avoid the top rate of tax, and Mr Smith said workers are already looking at relocating.

Graeme Leach of the Institute of Directors said: ‘The 50 per cent rate is a policy that should never have been announced. The indirect impact on entrepreneurial aspiration, business confidence and foreign investment is likely to be significant.

‘We suspect that little or no money will be raised and we urge the next government to reverse the increase as soon as possible.’
London today ranks sixth out of the eight key financial centres, in terms of the tax burden for high earners.

But when the new rate comes into force the UK jumps to the top of the list with the most onerous tax burden for any worker earning £500,000 or more.