Mayor of London Sadiq Khan has reiterated his pledge to protect green open spaces and urged local authorities to reject “inappropriate development”.

Asked for the Labour mayor’s thoughts on a new development plan for Waltham Forest that designates five acres of Metropolitan Open Land (MOL) for housing, a spokesperson from his office told the Echo that Sadiq would use his “full range” of planning powers to protect such space.

The spokesperson said: “The mayor believes that the strongest protection should be given to London’s Metropolitan Open Land and any inappropriate development should be refused. Working with his planning team, the mayor will continue to use a full range of planning powers to protect open and green spaces in applications referred to him.

“He will be making the most of brownfield sites across the city, which are ripe for building the homes Londoners so urgently need.”

Labour-led Waltham Forest Council has been in discussions with Lee Valley Regional Park Authority (LVRPA) about rezoning an area of MOL, adjacent to the Waterworks Nature Reserve on Leyton Marshes, for housing. LVRPA is keen to sell the land to fund its new ice rink in Lea Bridge Road.

At the end of January a petition against the ‘Lea Valley Eastside’ proposal was submitted to the council by campaign group Save Lea Marshes. It had been signed by 4,651 people, but continued to be signed online during February and has now well surpassed 5,000 signatures.

Waltham Forest Council has a policy of debating petitions submitted with more than 4,000 signatures, but has so far denied Save Lea Marshes the chance of a debate because not all the people who signed it live or work in the borough. A letter sent by the council to lead petitioner Abigail Woodman, and seen by the Echo, states: “Your petition does meet the threshold for a council debate”.

Save Lea Marshes is contesting the council’s decision to refuse a debate on the basis that the marshes – which also lie within Hackney and Haringey boroughs – are a public amenity enjoyed by people from all over London, not just Waltham Forest.