Boris Johnson has pledged to help make housing more affordable in the capital with plans to build 50,000 cheaper homes in the next three years.

Launching his housing manifesto at the Royal Institute of British Architects today, the Conservative mayoral candidate also said he would be working with local councils to deliver more family-sized homes.

"If we are to improve the quality of life for all Londoners then we must do something about the impact housing has on the rising cost of living," he said.

"Affordable housing must be more than decent'; it must be desirable."

Mr Johnson's plans involve a £130m scheme to help low-paid Londoners get on the housing ladder and to bring more than 84,000 empty homes back into use.

The Tory candidate also proposes tough new planning rules to stop development on London's green belt and gardens as well as more affordable retail outlets for independent shops.

He added: "I will adopt a fresh approach to housing in London to build varied and vibrant communities, not just tick boxes."

Rival Ken Livingstone accused Mr Johnson of copying similar policies already laid down by the London mayor.

He said: "The core of Boris Johnson's policy is the repeated proposal over several months to abolish the policy that 50 per cent of all new housing should be affordable housing and this will have a devastating effect on Londoners."