Developers could be set to make a grab for Barnet homeowners’ gardens on the back of Mayor of London Sadiq Khan’s housing policy, according to local Conservatives.

A developer, Sonar Property Development, has sent a letter to homes in the borough quoting the mayor and stating “we have identified your garden as a potential development site”.

The letter claims homeowners could have the chance to earn “a huge amount of money” as well as helping future generations to own their own homes by allowing development in their gardens.

Barnet Conservatives have warned people could be pushed into selling their gardens and hit out at Labour councillors for voting against their objections to the mayor’s Draft London Plan at a meeting of the Policy and Resources Committee on February 13.

But Labour has dismissed the Tories’ claims as ‘scaremongering’ and said the Conservatives had misunderstood the mayor’s policies.

The developer’s letter quotes Mr Khan’s statement: “I am using all of the powers at my disposal to tackle the housing crisis head on, removing ineffective constraints on homebuilders so we make the most of precious land in our capital.”

The Conservative group points out that the Draft London Plan contains a presumption in favour of “infill development within the curtilage of a house” for up to 25 homes, and claims this means developments would receive automatic planning permission.

Conservative councillor Richard Cornelius, leader of Barnet Council and chairman of the Policy and Resources committee, said: “This is exactly the kind of thing we feared would happen, which is why I was very disappointed that Labour councillors voted against our objections when they were presented to the Policy & Resources committee on February 13.

“They effectively voted for houses in back gardens, more flat conversions, and fewer parking spaces — which residents should remember when they vote on May 3.”

Cllr Ross Houston, deputy leader of Barnet Labour Group and housing spokesperson, said: “This is a complete misunderstanding of what the policy says.

“The mayor wants to provide more housing, and the plan is quite strict about using brownfield sites.

“The mayor is only allowed to intervene on big schemes. All he is saying is if you are going to give planning permission for a development in a garden, you have to make sure that green space is re-provided.”

Cllr Houston said the Conservatives had to resort to attacking the mayor rather than relying on their record in government.

He added: “The Tories are desperate to cling to power. It is either a complete misunderstanding or scaremongering.”

The councillor said the accusations about Mr Khan fit the Conservatives’ narrative of the mayor as being an “enemy of the people”.

A spokesperson for the Mayor of London added: “This is shameless scaremongering from Barnet Council who have an utterly appalling record of failing to deliver affordable housing for local people.

“The mayor makes no apologies for being bold about building affordable housing, but to imply that the London Plan is a ‘garden grab’ is deliberately misleading. It is private homeowners - not developers - who can build in their gardens, which they have been able to do since the current government relaxed the national rules.

“Barnet Council is trying to scaremonger local residents rather than helping the mayor build the new genuinely affordable housing those residents desperately need.”