The 2016-21 funding programme represents the biggest housing deal ever secured by City Hall, rising from £1.1bn previously allocated over the 2015-2018 period.

His target of 90,000 low cost homes by 2020-21 represents a 48% increase from the number of affordable homes built between 2009-10 and 2014-15.

The Mayor is also today launching new planning guidance, setting out for the first time an innovative approach both to speeding up decisions in the planning system as well as supporting build to rent schemes.

It will basically heavily scrutinise projects with less than 35% affordable housing and apply a light touch approach to schemes planning more than 35%.

Following negotiations with government, new rules mean investment in London can now be spent on a mix of homes for low-cost rent and affordable homeownership.

Most homes in the Mayor’s programme will be delivered by housing associations, with the condition that their plans must include a minimum 50% affordable housing, with some partners enabled to deliver at least 60%.

The Mayor said the Supplementary Planning Guidance was the first step to raising affordable housing levels from the low level of 13% given permission.

The guidance has been developed since the Mayor took office in May through extensive discussions with councils and the housing industry.

Khan, said: “I have been clear that fixing the housing crisis will be a marathon and not a sprint, but I am determined to lead from the front and get on with building genuinely affordable homes for Londoners to rent and buy.”

Ian Fletcher, Director of Policy at the British Property Federation, said: “The GLA has led the field in seeking to have a planning policy on Build-to-Rent and this latest guidance is immensely helpful to the sector and the Boroughs with which it works.

“When you are trying to do something new in housing inevitably you need to develop understanding, and the Mayor, his Deputy and team have wanted to be at the forefront, working with planners and investors to cast a sensible planning policy. 

“What you want as a developer or investor, such as a pension fund, is clarity and understanding that rental homes are different to those for-sale, which this guidance delivers.

“The sector wants to deliver tens of thousands of quality rental homes for Londoners, and those at discounted market rent, in a tenure blind manner. Recognising the sector and how it works in this guidance is a big help.”

Build to rent developer Greystar’s managing director, Mark Allnutt, said: “We welcome the news that London is receiving a £3.15bn allocation for affordable housing, and that the rules have been relaxed to allow this to be used across a wider range of housing types for rent as well as sale.

“London not only needs more rental accommodation, but more of this needs to be designed, built and managed for that purpose. Greystar rental communities offer first class apartments and amenities to suit people at different stages in their lives across a wide range of rent levels.”