Minister Lord Myners has warned that a US-style levy on banks could still be slapped on the UK.
His comments came after Chancellor Alistair Darling had appeared to rule out the move.
US president Barack Obama is hitting US banks with a 0.15 per cent charge on liabilities in a bid to recoup at least $90bn (£55.3bn) of taxpayers' money spent on bailing out struggling lenders.
When asked if the UK had ruled out copying the US system Myners told BBC Radio 4 that ministers wanted to "promote a global debate about this."
"We are looking at a very broad range of principles because these are areas where we have to work as part of an international co-ordinated response," he said.
"Because we do not want to disadvantage the UK in an industry – banking and financial services – in which we have global leadership."
Darling indicated last week that the British Government would not be following the US example.
He said: "No, we are not. The Americans are doing something different."
The Conservatives have said they would only impose a levy if all other major economies followed suit.