Government plans to allow more extensions in back gardens have been slammed by Sutton Council.

The council has joined neighbouring Richmond in attacking the coalition government's proposals to relax planning laws for a three-year period.

Councillor Ruth Dombey, leader of Sutton Council, said: "These proposals are a recipe for disaster. They have not been properly thought through."

The council believe it could lead to neighbourhood building disputes.

The coalition government outlined proposals to change planning rules last month in a bid to help the construction industry and homeowners.

Sutton Council has urged businesses and homeowners to check if planning permission is required before carrying out work.

If the proposals become law, business premises would be able to expand by 100sq metres and industrial units by 200sq metres without planning permission. Offices would be permitted to convert to residential use all without planning permission, regardless of the impact they will have on a neighbourhood.

Councillor Dombey said: "If this is allowed to happen it will set neighbour against neighbour and split communities for years to come.

"On top of the resentment and loss of quality of life, some people’s houses will also plummet in value if they’ve got no light or a noisy factory is within a few metres of their front door."

Councillor Jayne McCoy, chairwoman of Sutton Council's housing spokeswoman, said: "It would be desperately premature to start any building project without checking whether planning permission is required on the basis of this announcement."

"There is no evidence that this will do anything to promote economic growth and I strongly advise that anyone considering a project seeks advice, otherwise it could prove very costly."