Labour has stepped up calls for the Government to drop its planned cut in the top rate of tax.
The party released details of its private polling showing that 71% opposed the reduction from 50p to 40p for earners on more than £150,000 a year, due to come in next April.
The survey by pollsters ICM found opposition was almost as high among Tory voters, with 65% against the cut going ahead.
Shadow Cabinet Office minister Michael Dugher said: "In tough times David Cameron has chosen to give 8,000 people earning over £1 million a tax cut of at least £40,000. Meanwhile, millions pay more and his failed economic plan has taken us into the longest double-dip recession since the Second World War.
"This isn't fair. We need a One Nation prime minister who will take decisions in the interests of the whole of Britain, not one who puts millionaires before the millions."
He said Mr Cameron and other Cabinet ministers should "come clean" about how much personally they stood to benefit from the reduction.
Labour said ICM interviewed 2,009 people in Great Britain online on October 3 and 4.