In yesterday's Budget speech, George Osborne announced a new 7% rate on homes costing £2million or more from 22 March 2012.
This equates to a £140,000 tax bill on a £2m house.
During the speech he also announced measures to clamp down on schemes that attempt to avoid stamp duty.
He described stamp duty avoidance as "morally repugnant" and said those who buy £2million plus properties through a company, will be hit with a punitive 15% charge.
To ensure overseas and well-off buyers pay stamp duty, George Osborne added a warning that he would act "swiftly, without notice and retrospectively" if wealthy individuals or their accountants managed to dream up underhand ways of getting around the rules.
He also announced legislation to close down another loophole known as "sub-sale relief" that could allow some people to escape tax.
London is likely to be hit hardest by the new 7% rate as it is estimated that 75% of all the homes sold in the last two years at £2 million or more were in London.
The two-year stamp duty holiday for first time buyers that is due to end on 24 March 2012 is not being extended.
Since March 2010, first-time buyers have enjoyed exemption from the 1% duty on homes bought for less than £250,000.
