Josef Ackermann, chief executive of Deutsche Bank, has broken the banking industry's public silence about how it will deal with the UK's controversial supertax on bonuses, saying that he will spread the pain of any bonus cuts among staff in New York, Frankfurt and Hong Kong, as well as London.

“We will clearly globalise it,” Mr Ackermann told the Financial Times in an interview. His remarks risk angering staff outside London.

“If parts [of the cost of the tax] are paid out of the bonus pool we would seek to globalise it. It would be unfair to treat the UK bankers differently.”

Alistair Darling, the UK's chancellor of the exchequer, last week announced a surprise 50 per cent supertax to be levied on banks' bonus pools, in an effort to curb banker remuneration in a year when profits have been artificially buoyed by the direct and indirect effects of government bail-outs.

Banks and their staff have been furious about the tax ever since. If its cost is passed on to bankers, bosses say they are trapped in a Catch-22 situation – either UK bankers feel disgruntled at being paid less than US peers, or New York bankers are punished indirectly by the UK government. Some lawyers and tax experts have said the affair could lead to a transatlantic political row.

Mr Ackermann admitted that a chunk of the tax hit could well be borne by Deutsche's investors. “We will monitor what [other] banks are doing, how much of the cost will be borne by staff and how much will be taken by shareholders. That is absolutely undecided.” Several US banks have said privately that they, too, are considering absorbing the cost of the tax.