Sadiq Khan will announce plans to allow housebuilding on parts of London’s green belt in a significant shift in housing policy, as he warns the capital faces “the most profound housing crisis in its history”.
In a major speech on Friday, the Mayor of London will argue that longstanding restrictions on green belt development are outdated and unsustainable, and that a bold new approach is needed to meet the city’s housing needs. London needs to build around one million homes over the next decade, he will say — far beyond what can be achieved by brownfield development alone.
“The status quo is wrong, out-of-date, and simply unsustainable,” Khan is expected to say. “Development on carefully chosen parts of the green belt — done in the right way — would allow us to unlock hundreds of thousands of good-quality new homes for Londoners.”
This marks the first time City Hall has explicitly backed the strategic release of low-quality or inaccessible green belt land, particularly those near existing or planned transport links, to build new affordable homes.
London is currently building just 35,000 homes per year — less than half the 88,000 needed annually to meet demand. While reaffirming his commitment to prioritising brownfield development, Khan acknowledged this alone is not sufficient.
The policy will feed into a broader public consultation on the next London Plan, which sets out how the capital will evolve over the next 20 to 25 years. A city-wide review of green belt land has also been commissioned in line with government requirements.
Khan insisted that building on selected green belt sites does not contradict his aim of being “the greenest mayor London has ever had”. He pledged that any new developments would improve biodiversity and result in a net increase in genuinely green and accessible land.
The plans have already received high-level support. Angela Rayner, Deputy Prime Minister and Housing Secretary, said the government welcomes the “bold” move, calling it “an ambitious response to a critical challenge”.
“We cannot end the housing crisis and build the 1.5 million homes we need without London being ambitious in its approach,” she added.
The Local Government Association, London Councils, and housing groups such as Generation Rent have also expressed support. Ben Twomey, CEO of Generation Rent, said the plan could help curb sky-high rents and prevent poverty and homelessness.
However, green space campaigners urged Khan not to sacrifice local parks, playing fields, or farmland, particularly in areas already underserved by public green space.
Roger Mortlock, chief executive of countryside charity CPRE, said the solution lies in reforming the housing market and ensuring developers meet targets for genuinely affordable housing.
“The answer isn’t to build on local parks, playing fields and farmland,” he said. “It’s to transform the market and hold developers to account.”
Others, including Kate Ashbrook of the Open Spaces Society and Shaun Spiers of Green Alliance, suggested that any reclassified green belt should be enhanced to include green spaces and nature access, ensuring urban communities benefit from a healthier environment.
“The housing crisis is breaking families apart”
Khan acknowledged the policy’s potential controversy but urged Londoners to “keep an open mind” and consider the human cost of inaction.
“We have young professionals stuck living in their childhood bedrooms, couples forced to leave the city to raise a family, and London primary schools closing because families can’t afford to live nearby,” he said. “It breaks my heart. The damage the housing crisis is causing is pervasive and profound. We simply cannot let it continue.”
The Mayor’s remarks come amid growing concern that rising prices, limited supply, and sluggish development are driving a new generation of Londoners out of the city, eroding its social fabric and economic resilience.
The proposal will now go to public consultation as part of the next iteration of the London Plan, setting the stage for a city-wide debate on the future of housing, land use, and what it means to build a livable London.
