A developer has bid to turn an office at a former garden centre into a home without planning permission on a stretch of beloved open land known as Highgate Bowl.

Omved International Ltd is seeking to use controversial permitted development rules to change the status of an office on the site of the former Highgate Garden Centre so it is classed as a residential property. The developer would still need formal planning permission if it was to make alterations to or demolish the property, known as Whistler’s Cottage.

Highgate Society vice-president Michael Hammerson said: “We are always worried about the Bowl.”

He added: “We’re not sure why they’re doing this. Whether it’s a preliminary to anything else for the site, we don’t know, but we will be discussing it. We don’t want them to convert the whole site to residential.”

Six months ago, the Planning Inspectorate rejected the developer’s bid to build three luxury homes on the site, off Townsend Yard.

Omved International had appealed to overturn Haringey Council’s 2013 decision to refuse planning permission.

Campaigners have been fighting plans to develop the land for roughly 50 years.

They hope to raise enough funds to buy the Bowl from developers to protect it for future generations.

Omved International, which is based in the British Virgin Islands, did not respond to a request for comment.