The Liberal Democrats are planning to launch a £4 billion double raid on the incomes of the wealthy, with up to three punitive rates of taxation on large homes and a new tax grab on pensions.
Treasury Chief Secretary Danny Alexander is planning to use plans drawn up by Treasury officials to argue the case for up to three new Mansion Taxes.
The Lib Dems are already committed to imposing a 1 per cent levy on the value of homes over £2 million, expected to raise £2 billion.
But senior party sources have revealed that Mr Alexander is now plotting to bring in one and perhaps two higher rates, to hit people with homes worth more than £5 million or £10 million with even higher tax rates.
The Lib Dems also want to raise another £2 billion by raising tax on pensions saving.