Mayor of London Boris Johnson has urged the government to reconsider lifting restrictions on turning offices into homes in parts of the capital.

Johnson last year negotiated for four areas in central London to be exempt from the permitted development rights policy, which allows developers to change the use of a building without planning permission.

These areas included the central activities zone, which incorporates the City of London, the South Bank and the West End, the commercial area north of the Isle of Dogs and London’s enterprise zones in the Royal Docks, plus the part of the City Fringe in east London.

But the government has just finished consulting on proposals which could see these exemptions removed - a move that the mayor says would damage London’s internationally important business locations.

In a letter to the secretary of state for communities and local government, Eric Pickles, the mayor, together with London First, the British Property Federation and the Planning Officers Society London said that “incremental unplanned loss of office accommodation in strategically important office areas of London can significantly weaken the agglomeration benefits provided by these locations”.

The letter also said that criteria should be in place to protect other, strategically important business locations across the country.

Faraz Baber, director of planning policy at London First, and a signatory to the letter, said: “We see merit in expanding permitted development rights , such as the ability to change land uses in the high street (like turning shops to banks and vice versa) without going through the planning process.

“But we have serious concerns over the proposal to remove existing exemptions from PDR in areas like the central activities zone. These internationally recognised hubs of economic activity have a finely balanced mix of land uses that are carefully managed by the planning process. They must remain managed through the planning system.”

Liz Peace, chief executive of the British Property Federation, said: “The relaxation of permitted development rights is a key part of the government’s move towards speeding up and streamlining the system and encouraging new housing to come forward in the current crisis, but, it’s important to maintain thriving commercial areas in which people can work and play too.

“We should not underestimate the importance of agglomeration for businesses as productivity rises when places of employment are in close proximity to one another.”