With the Bank of England determining interest rates, the only effective control of the housing market central government has is the setting of Stamp Duty rates.
As the government wants to stop the housing market, particularly in the South East, from over heating it is widely believed that stamp duty will be increased in the next budget, especially in the middle and top bands.
Levied against the purchase price of a property, the current rates are:

With an average national house price of less than £100,000 it is widely thought the lowest band will be left unchanged. However, an increase of just 0.5% on the top band would result in increased revenue to the exchequer of £550,000 from Mayfair alone, based upon last year's figures where approximately £110m worth of residential property was sold in Mayfair with a price in excess of £500,000.

Mayfair is continuing to see new residential properties created and Wetherell are instructed to market for sale a number of new developments.
1 Carlos Place (fronting Mount Street) is a refurbishment of a classical Mayfair building where traditional architecture is complemented by modern design. Comprising ten flats (6 x three bedroom apartments and 4 x one bedroom flats) a show flat is available for viewing, asking price £1,300,000.
Some of the finest penthouses available in recent years have been released at Carlton Gardens in St. James's. Occupying the top two floors of a newly constructed building designed by Sir James Stirling, the six apartments (four with terraces) have unique views and underground parking, with prices starting at £3,000,000.
Later in the year will be nine new apartments in a building off Piccadilly completely rebuilt behind a listed facade plus a number of houses currently undergoing extensive refurbishment.

The price paid for a property is shortly to become available in Britain. Whilst some vendors and solicitors may cite invasion of privacy as an argument against the implementation of price paid, similar information is available in most of Europe - and Scotland, where it doesn't appear to cause any problems.
Land Registry will provide the information but only for applications received on or after 1st April 2000 will the price paid appear - it will not be entered retrospectively. Likewise, it will only show the last price paid and any previous prices will be removed from the register.