What is the greenbelt and why are Labour's plans controversial?
10 May 2025, 09:25 | Updated: 11 May 2025, 11:45
Sir Sadiq Khan has called for a "bold new approach" to housebuilding that could see construction on greenbelt land for the first time.
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The Labour Mayor of London has said that he is "actively exploring" construction on some of the protected areas to help meet a target of 88,000 homes per year in the capital.
“I'm announcing a bold new policy today and I'm consulting Londoners about this, which is to actively seek those parts of the greenbelt we can release to build the homes we need with the conditions attached,” Sir Sadiq told LBC’s Fraser Knight.
“I'm not willing to duck this difficult political choice,” he added in reference to needing to step up the construction from the current level of around 40,000 homes per year.
NEW: London Mayor @SadiqKhan tells @LBC that the cost of homes will continue to rise if we don’t start building on the city’s greenbelt.
— Fraser Knight (@Fraser_Knight) May 9, 2025
He says the controversial move is a ‘politically difficult’ one but says he ‘won’t shy away from doing what’s right’. pic.twitter.com/x6r3106kqX
“I'm not willing to let down a generation of Londoners who can't afford to rent, let alone buy in our city. I've met too many adults, professionals in great jobs, living in their childhood bedroom.
“I bet too many couples who are choosing between having a child or having to leave our city. I bet too many families living in damp and mouldy accommodation.
“On average, every classroom in London has a child who's in temporary accommodation. We've been building record numbers of homes in London on brownfield sites, but it's not enough to meet the needs of our city.”
Sir Sadiq has said he has no other option than to consider this action but any move to build on the green belt is likely to draw a reaction from conservationists and environmentalists.
Here is what you need to know about the greenbelt and why building on it is controversial.
What is the Greenbelt?
The greenbelt is a designated area of land that has been protected from forms of development.
There are 14 such areas across the UK as set out by the 1947 Town and Country Planning Act although London has further defined boundaries designated under a 1938 statute.
The green belt is literally that around London - forming a ring around the capital that takes in Epping Forest, Richmond Park and the Chiltern Hills.
It is different to greenfield sites which are greener sites that have had little prior development but are not subject to such rigorous restrictions.
Councils are restricted on their planning by the boundaries of the Green Belt but central government can overrule this when they need to press through with projects.
There are also brownfield sites, prioritised by the government for building, which are urban or examples of land in poor condition.
What is Sadiq Khan looking to do?
Under Sir Sadiq’s proposals, London’s planners will look to release some green belt land for house building. But it will come with conditions on affordable housing, energy efficiency, transport links and promoting access to green spaces such as parks.
The announcement marks a change in stance for Sir Sadiq, who has previously argued against releasing green belt land while there are still previously developed brownfield sites available.
He said: “We've actually looked at some of the greenbelt across and around our city. The size of the greenbelt outside of London, just touching London, is three times the size of London within London, it's more than a fifth. But it's not all green and pleasant, it's not all rich with wildlife. It's normally poor quality, badly maintained, inaccessible to Londoners.”
Pressed by Fraser on where poorly maintained greenbelt examples are, he did not state anywhere specifically but did clarify that “no one's talking about touching any of our gorgeous parks”.
He added: “So people know my record in terms of the environment, in terms of nature, but I think nature and homes go hand in hand. I think it's a false choice to choose between house building and protecting the environment.”
City Hall has already begun a review of green belt land in line with the Government’s policy of building more on low-quality parts of the green belt, so-called “grey belt” land.
Sir Keir Starmer has previously identified grey belt land as a potential focus for development as the government looks to build 370,000 homes per year.
The prime minister set out that for the green belt to be encroached upon, any development must include suitable road access, GP surgeries, local school and nursery facilities, and a high level of social and affordable housing.
His deputy Angela Rayner said: “We must all do our bit and we must all do more. We expect every local area to adopt a plan to meet their housing needs.
“The question is where the homes and local services people expect are built, not whether they are built at all.”
What is the Greenbelt?
The greenbelt is a designated area of land that has been protected from forms of development.
There are 14 such areas across the UK as set out by the 1947 Town and Country Planning Act although London has further defined boundaries designated under a 1938 statute.
The green belt is literally that around London - forming a ring around the capital that takes in Epping Forest, Richmond Park and the Chiltern Hills.
It is different to greenfield sites which are greener sites that have had little prior development but are not subject to such rigorous restrictions.
Councils are restricted on their planning by the boundaries of the Green Belt but central government can overrule this when they need to press through with projects.
There are also brownfield sites, prioritised by the government for building, which are urban or examples of land in poor condition.
What is Sadiq Khan looking to do?
Under Sir Sadiq’s proposals, London’s planners will look to release some greenbelt land for house building. But it will come with conditions on affordable housing, energy efficiency, transport links and promoting access to green spaces such as parks.
The announcement marks a change in stance for Sir Sadiq, who has previously argued against releasing greenbelt land while there are still previously developed brownfield sites available.
He said: “We've actually looked at some of the greenbelt across and around our city. The size of the greenbelt outside of London, just touching London, is three times the size of London within London, it's more than a fifth. But it's not all green and pleasant, it's not all rich with wildlife. It's normally poor quality, badly maintained, inaccessible to Londoners.”
Pressed by Fraser on where poorly maintained greenbelt examples are, he did not state anywhere specifically but did clarify that “no one's talking about touching any of our gorgeous parks”.
He added: “So people know my record in terms of the environment, in terms of nature, but I think nature and homes go hand in hand. I think it's a false choice to choose between house building and protecting the environment.”
City Hall has already begun a review of green belt land in line with the Government’s policy of building more on low-quality parts of the greenbelt, so-called “grey belt” land.
Sir Keir Starmer has previously identified grey belt land as a potential focus for development as the government looks to build 370,000 homes per year.
The prime minister set out that for the greenbelt to be encroached upon, any development must include suitable road access, GP surgeries, local school and nursery facilities, and a high level of social and affordable housing.
His deputy Angela Rayner said: “We must all do our bit and we must all do more. We expect every local area to adopt a plan to meet their housing needs.
“The question is where the homes and local services people expect are built, not whether they are built at all.”
