New target for cheap housing

●As mayor, Ken Livingstone set a London-wide target of 50 per cent affordable housing. However, Boris Johnson dropped this target at the first chance he got, claiming it was a barrier to development and only ever hit 34 per cent anyway.

●Under Mr Livingstone's scheme, builders had to make half of the properties in any new development available at a much cheaper rate.

●At Chelsea Barracks, one of the most high-profile developments to include affordable housing, at least 319 of the 638 apartments on the 13-acre site should be classed as "affordable" - offered through a shared-ownership scheme, as rent-to-buy or for prices "within reach".

●Mr Johnson's decision that a "one-size-fits-all" target from City Hall was unsuitable in the current market means he will now open negotiations with London boroughs to agree his own 50,000 affordable homes target by 2011.