LONDON, July 27 (Xinhua) -- A whole generation of Londoners are being blocked from enjoying the benefits of a good quality affordable home, London Mayor Sadiq Khan said Friday.

New data released by City Hall said that accessing social housing or homeownership is now a pipe-dream for many people in Britain's capital city.

Khan has called on the Prime Minister Theresa May's government to hand over billions of dollars it collects every year in a tax on property sales known as stamp duty.

If stamp duty proceeds were devolved to London it would help Khan reach the 3.6 billion U.S. dollars a year he needs to build thousands of affordable homes a year in the capital.

Khan said: "London's rocketing house prices mean we are contributing billions of pounds in stamp duty to the Treasury, when we could be using it to build new social rented and other genuinely affordable homes."

The mayor added that control of stamp duty has been devolved in Scotland and Wales and it's vital government ministers devolve it to London, which has a population larger than Scotland and Wales combined.

The capital's rising housing costs now generate 4.5 billion U.S. dollars a year in stamp duty receipts.

The data show that the number of families living in social housing, has fallen from the largest in the 1980s to the smallest.

At the same time the home ownership divide has grown starkly between younger and older Londoners.

International cities with more control over their own tax revenues outpace London's housing growth, pointing to an alarming housing inequality, says the mayor's report.

The 2018 "Housing in London" report shows that since a Right to Buy scheme was introduced in 1980 more than 300,000 social homes have been sold by councils in London, with just one in five having been replaced in the housing stock.

It means that social housing now only accounts for one-in-five homes in London. It has also meant the numbers of private rented households with children have more than doubled in a decade, from 140,000 in 2007 to 320,000 in 2017.

In 1990, around half of London households headed by a house-owner aged 25-34, but the proportion of young people owning their own home has fallen to around a quarter of the total.

Khan said: "London's housing landscape has worsened dramatically over the past 30 years, and we now risk a whole generation of Londoners being blocked from enjoying the benefits of a good quality, genuinely affordable home."

Terrie Alafat CEO of the Chartered Institute of Housing said: "Young people are paying the price for our national failure to build the genuinely affordable homes we so desperately need, particularly in London. We cannot go on with the system we have or the implications for future generations will be every bit as significant as the impact of Brexit."