The frozen housing market needs millions of pounds of public money to kickstart it, according to London mayor Boris Johnson.
Announcing a £135 million scheme to help people in the capital buy their own homes, he said: "It's a route to buy. It's a right to buy.
"The idea is to help people get on the housing ladder and jump-start the housing market."
He told BBC News the market was "completely glacial".
The scheme will bring around 3,000 new affordable homes on to the market.
Around £93 million will go towards five regeneration projects on estates in London.
The rest of the money will go to a scheme offering 500 homes at discounted rent, allowing their occupiers to save up the money needed to buy them.
Mr Johnson said: "The money we are investing today is also a major shot in the arm for London's development sector and the economy. As this rolls out, thousands of construction sector jobs will be saved, but more importantly the sector will emerge strong to build and grow London when the recovery comes."
The mayor warned against "hasty and ill-thought out regulation" of the banking sector, but said former Royal Bank of Scotland (RBS) boss Sir Fred Goodwin should donate his pension to charity.
He added Sir Fred would improve the public image of banking if he donated his £693,000 annual pension to the Mayor's Fund for disadvantaged children in London.