Calls for Conservators charged with protecting Wimbledon and Putney Commons to resign have been made after they were accused of selling off land they are supposed to protect.

The Friends of Putney Common (FoPC), formed to protect the green space from inappropriate development, successfully quashed permission for construction of a 420-pupil school and 24 luxury flats on the derelict Putney Hospital site in the High Court in March.

During the process the FoPC claimed Wimbledon and Putney Commons Conservators (WPCC) did not have permission to allow Wandsworth Council to create a private road through Putney Common to be used by construction vehicles.

Hundreds of Putney residents also objected, stating common land should not be sold or loaned for any purpose, particularly by those elected to protect it.

In total 46,000 households live in the “commons levy area” and each one has to pay a higher council tax rate meaning the WPCC receive more than £1m a year.

Part of the controversial plan included a payment of £350,000 to the WPCC for the access road to be created.

The two groups clashed at the Conservators annual general meeting last week, with accusations the WPCC was working for the council.

John Cameron, from the FoPC, said: “The Conservators need to either resign or rethink their responsibilities, particularly when so many of their levy payers oppose their strategy and have never been formally consulted on their views.

“The Conservators lack of commitment to the one thing they are meant to do – to protect and preserve Putney Common – is a disgrace.

“The concern of residents is the over-intensive use, only made possible by the Conservators selling rights to a substantial area of land, which will be lost to the common forever. A large area of Putney Lower Common will become urbanised; tarmacked roads with electronic barriers, security bollards and ditches, new tarmac footpaths with street lighting.”

David Devons, vice-chairman of the WPCC, countered claiming the common is not losing land as land is being returned on Stag Lane, Roehampton, 3km away.

He also said the WPCC has not sold land, though confirmed his group had received £350,000 to provide access to the hospital site.

He said: “The Conservators have been open about these developments as can be seen from their annual newsletters and their annual report and accounts from 2006 onwards.

“The role of the Conservators is indeed to protect the Commons. “The Conservators are neither on the side of, or against, the council. It is the council that owns the Putney Hospital site, not the Conservators.”

Mr Cameron disputed this: “This ‘compensation land’ is already all common land and registered as such at HM Land Registry. The statement is meaningless spin, trying to give the impression they’re gaining land.”