The unique London Housing Bank scheme would loan up to £200m to development partners to help them speed up the building of around 3,000 homes on large scale, multi-phase schemes, which already have planning consent.

These homes would then be let to Londoners at low cost rent for up to 10 years before being sold on, with the loan repaid to City Hall.

The idea follows research conducted by City Hall that found planning consents have been granted for around 200,000 homes in London which have not yet been built.

This figure that is sometimes confused with developers land banking sites. But around three quarters of these consents are on large, multi-stage regeneration developments of more than 500 homes, which can take many years to complete.

Often this is due to the funding and sales constraints which can limit the pace of building.

Johnson, said: “We’re doing everything we can to double house building across the capital and address a 30 year failure to build enough homes for this thriving city.

“Through this exciting new fund we hope to provide thousands of brand new homes many years sooner than would otherwise be possible, and make them available to rent at more affordable, below market, rates for hardworking Londoners.”

This comes a week after the Mayor published his updated Housing Strategy setting out a long-term ambition to increase supply to at least 42,000 new homes per annum, around double what has been achieved over the last 20 years.

Of these, at least 17,000 should be affordable with 5,000 for purpose-built long-term market rent.

The Mayor is consulting agencies and organisations within the housing industry on the London Housing Bank proposals. The closing date for responses is the 21 May.