A learning disability charity could be forced to make way for an “alien” housing development on much-loved open land in Highgate, protesters have warned.

Critics say that the Harington Scheme, which runs gardening courses for young people with learning disabilities, could be under threat if plans to build three luxury homes close by are approved by Haringey Council.

The scheme sits near to the proposed development site, a former garden centre, in prize land known as Highgate Bowl.

Members of the Highgate Bowl Action Group, who are fighting the plans, said that if Haringey Council grant planning permission for three large homes, it would set an “irresistible precedent” for building on the rest of Highgate Bowl.

In an official response on the planning application, signed by the Harington Scheme’s co-chair Tony Baker, the group stated: “There can... be no doubt that to grant permission for any development... would set an irresistible precedent for the covering of the whole Highgate Bowl with housing development of a type alien and inappropriate to the historic core of Highgate Village, including the land currently occupied by the Harington Scheme.”

Planning consultants Michael Burroughs Associates were unavailable for comment.