Moves to protect gardens from development will set the mayor of London on a collision course with central government, according to the Royal Town Planning Institute

In the revised London Plan, published on Thursday, Boris Johnson set out a “general presumption” against building on gardens.

Michael Fearn, consultation secretary for the RTPI’s London branch, said: “If this gets through, it could make it harder for developers to develop. Boris’ move against the so-called ‘garden grab’ sets him on course for clashes with central government.”

Gardens are classified as brownfield land, which is prioritised for redevelopment under the government’s national planning policy.

Fearn added that the plan did not say how London would find land for 23,000 homes.

A spokesperson for the communities department said: “Councils can already set local policies that protect gardens and separate them out from brownfield development targets.”

Judith Damerell, a planning partner at solicitor Eversheds, warned that the change might cause problems for councils, which will have to "do their background work” into how best to achieve a balance between new homes and gardens.