It is expected that Chancellor of the Exchequer Alistair Darling will propose the tax on earnings above $244,000 in his pre-budget report, The Daily Telegraph reported Tuesday.
"We had calls from bankers asking about what action they might take under the Human Rights Act," said Bill Dodwell, head of taxation at Deloitte, a financial consulting firm.
The rhetoric among policy makers and bankers over bonus checks has become sharper in recent days as the anticipated announcement on the so-called "supertax" comes closer.
The British Bankers' Association said tax pointed at one group -- bankers with large commission checks -- was "populist, political and penal."
But a source close to Darling said "we cannot be held ransom by the banks." Frequent newspaper stories are calling on bankers to "start living in the real world."
A source said Darling was not goaded into the idea by Prime Minister Gordon Brown.
Instead, it occurred to Darling that Group of 20 agreements to curtail bank salaries did not go far enough, especially when he learned of Goldman Sachs setting aside $18.5 billion for bonuses this year, The Guardian reported.