Trade body the House Builders Federation has stepped up its opposition to London mayor Ken Livingstone's proposal that half of all new schemes should be made up of affordable housing.
The HBF said government figures released this week showed that such stringent guidance would decrease rather than increase the number of homes built in London.

The figures indicate that 184,000 new households have been established in London in the past four years, whereas only 58,000 new homes were built. Fewer new homes were built in the UK last year than at any time since 1924.

The HBF said the planning system was primarily to blame, but it noted that Livingstone's decision to raise the percentage of affordable housing from 25% to 50% would deter landlords from selling land for residential schemes.

An HBF spokesperson said: "It makes no sense to ask developers to take on loss-making projects. They will simply walk away.

"Ken needs to realise that 50% of nothing is nothing."

In England as a whole, household growth of 785,000 over the past four years has exceeded expansion of the housing stock by 195,000.