A Wimbledon conservation group has accused Tory councillors of doing a u-turn on protecting green spaces after they spoke out in favour of a controversial housing development.

The plans, which were approved unanimously at a council meeting on April 17, allow developer Michael Shanly to build eight new houses at 14, The Downs, in Wimbledon Park. The company will also convert the site's 19th century convent building into five flats.

At the meeting Conservative councillor David Simpson, who represents Hillside ward, voiced his support for the proposal.

But Mark LeClerq, head of the Wimbledon Society, said: "It is my feeling that if this gets through then the whole principle of conservation areas is gone."

He accused Conservative councillors of ignoring an election pledge to protect Merton's 28 conservation areas, sites of significant importance that carry extra protection from development.

He claimed that approving the plans meant the loss of vital green space and also said that the decision was based on inaccurate information.

However, council leader David Williams rejected the claims as "a lot of nonsense". He said that his party were committed to protecting conservation areas, but the proposals met all relevant criteria and were backed by a significant number of residents.

Coun Williams added that turning down the proposal would have lead to a costly appeal by the developers that would eventually have to be paid for by the council.

"We have a responsibility not only to the people who object to something but also to the other tax payers we represent," he said.

He also accused some residents' of taking a "never never never approach" that was "unrealistic".

Kevin Scott, a spokesman for developers Michael Shanly, said that the company had held several consultations and talked to local people "extensively" about the plans.

But John Waller, a member of South Ridgeway Residents' Association looking at planning matters, said that the council had allowed "intensive development and continuous infilling" of sensitive sites.

"My view is that the council has failed to adhere to its policy of protecting conservation areas, despite assurances they have given," he said.

The site is occupied by nuns belonging to the order of St Anne. They are set to move to a new building in nearby Lansdowne Road.