George Osborne has warned against driving away the wealthy after Deputy Prime Minister Nick Clegg called for a temporary tax on the rich.
The Chancellor said he had already taken steps to ensure the UK's highest earners pay more but insisted it was vital to hang on to entrepreneurs who would fuel the economic recovery.
Mr Clegg has called for those of "very considerable" wealth to contribute more to turning around Britain's financial fortunes.
But during a visit to Sunderland, the Chancellor said: "I am clear that the wealthy should pay more which is why in the recent budget I increased the tax on very expensive property transactions.
"But we also have to be careful as a country we don't drive away the wealth creators and the businesses that are going to lead our economic recovery."
In an interview with the Guardian, Mr Clegg suggested people of "very considerable personal wealth" could make a "time limited contribution" as the country faced a "longer economic war".
"If we want to remain cohesive and prosperous as a society, people of very considerable personal wealth have got to make a bit of an extra contribution."
The Lib Dem leader is expected to flesh out his thoughts on a possible "wealth tax" at the party's conference in Brighton next month.
Party president Tim Farron said it could a new tax could be based on the compulsory declaration of assets.
"Either, we deal with (the economy) by making cuts that affect the majority who are not able to afford to pay for them, or we do it in a way which makes sure that those who are the best-off, for a shortish period of time, pick up an even bigger tab and that’s important that they do."
Senior Tory backbencher Bernard Jenkin attacked the idea, and said Mr Clegg's proposal could "strangle the goose that lays the golden egg".
Speaking to the BBC Radio 4 Today programme, he said: "If the politics of envy made a country rich, we would be a very rich country.
"I think most rich people are contributing far more in tax than other people. I know this is not a fashionable view, but if you go on raising tax on rich people, and that's why, in agreement with Nick Clegg we have had to cut the top rate of tax from 50p to 45p - you drive wealth abroad.
"This is a pre-conference easy clap line."
Chris Leslie, Labour's shadow treasury minister, said: "Nick Clegg is once again taking the British people for fools. He talks about a tax on the wealthiest, but he voted for the tax cut for millionaires in George Osborne's Budget."
