Owners of tens of thousands of properties in England valued at more than £2m are set to be hit with a surcharge of at least £2,500 from 2028, in what has been dubbed a mansion tax.
The annual charge will come on top of existing council tax, and will increase depending on the price of a property - with four separate bands.
These will go from the lowest band of £2m to £2.5m, with the highest for those valued at £5m or more, who will pay £7,500 a year - with the bulk of all the properties affected based in London.
In its assessment released in error ahead of the Budget, the Office for Budget Responsibility (OBR) expects the measure to raise about £400m a year by 2029-2030.
