Key Points
- Lambeth Council has written in support of Tower Hamlets’ legal challenge against the Mayor of London’s decision to reduce the affordable housing requirement for new developments.
- The decision under challenge cut the expected affordable housing requirement from 35 per cent to 20 per cent.
- The challenge is also backed by Lewisham Council and Hackney Council.
- Cllr Martin Abrams, Leader of Lambeth Council, said the shortage of social housing is causing “serious harm” in communities.
- Lambeth says it has more than 29,000 people on its housing waiting list and more than 4,275 homeless households in temporary accommodation.
- The council argues that lowering the requirement could weaken its negotiating position with developers and result in fewer affordable homes for Londoners.
Lambeth Council (South London News), June 29, 2026, has joined other London boroughs in supporting a legal challenge against the Mayor of London’s decision to reduce the affordable housing threshold for new developments. As reported by Lambeth Council and quoted in the material provided, the borough has written a letter in support of Tower Hamlets, which is leading the challenge over the reduction from 35 per cent to 20 per cent.
The issue centres on whether the lower requirement will undermine the delivery of affordable homes across the capital. The decision has already drawn backing from other councils that share similar concerns about housing pressure.
What does the legal challenge say about the housing cut?
The legal dispute is focused on the policy change itself, and on what it could mean for future housing delivery in London.
According to the information provided, Tower Hamlets is leading the challenge, with Lewisham and Hackney also joining. The councils argue that lowering the benchmark risks establishing a weaker standard as the default for negotiations with developers.
Their concern is that the change could reduce the number of affordable homes secured through planning decisions. The challenge therefore goes beyond one borough and raises a wider question about London’s housing policy.
What did Cllr Martin Abrams say?
As reported in the statement attributed to Cllr Martin Abrams, Leader of Lambeth Council, the shortage of social housing is already “creating serious harm” in local communities.
He said that people with the least are being denied “the fundamental right to a stable home” from which to raise families and build a future.
Abrams also said Lambeth has more than 29,000 people on its housing waiting list and more than 4,275 homeless households living in temporary accommodation, which he described as a “real crisis.”
He added that cutting the affordable housing requirement would “lock in a lower standard as the new norm” and weaken the council’s hand in talks with developers.
How many people are affected in Lambeth?
The figures cited by Lambeth Council suggest the borough is under intense housing pressure. More than 29,000 people are on the waiting list for housing, while more than 4,275 homeless households are being housed in temporary accommodation, which the council says is often poor quality.
These numbers were used to underline the scale of need behind the council’s support for the legal action. The council’s position is that any reduction in affordable housing expectations will make it harder to meet that need.
What does this mean for developers and housing delivery?
Lambeth’s argument is that a lower affordable housing threshold could change the way councils negotiate with developers on individual schemes.
If the 20 per cent target becomes the accepted norm, councils may have less leverage to push for a higher proportion of affordable units.
That could affect the overall balance of housing being built in London, particularly in areas where land values and development pressures are high. The councils involved say that outcome would likely mean fewer affordable homes, not more.
What is the wider London context?
The challenge reflects a broader debate over how London should address its housing shortage. Boroughs facing long waiting lists and high temporary accommodation use are warning that reduced affordable housing expectations could worsen the situation.
Support from multiple councils indicates that the issue is not limited to one area, but is part of a wider policy dispute across the capital.
The case also highlights the tension between encouraging development and securing homes people can actually afford.
Background to the development
The development follows the Mayor of London’s decision last year to reduce the affordable housing requirement on new developments from 35 per cent to 20 per cent.
That change prompted the legal challenge now being supported by Lambeth Council, along with Tower Hamlets, Lewisham and Hackney. The boroughs’ criticism is that the lower requirement could reshape future negotiations and reduce the number of affordable homes secured through the planning system.
The dispute sits within long-running pressure on London councils to deliver more social and affordable housing while dealing with rising demand and homelessness.
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What could happen next?
If the legal challenge succeeds, it could force a reconsideration of the current affordable housing policy and potentially strengthen boroughs’ position in future planning negotiations.
If it fails, councils may have to work within the reduced 20 per cent requirement, which they fear could limit affordable housing delivery. For residents on waiting lists and households in temporary accommodation, the outcome could influence how quickly affordable homes come forward over time. For developers, the ruling could affect planning expectations and the financial structure of new schemes in London.
