Protesters claiming that Tooting's Graveney School excludes local pupils in favour of a middle-class "elite" have failed to force a change in its selection policy.

Friday's decision marks the second time in two years that a Government-appointed adjudicator has had to rule on local parents' objections.

An exasperated Wandsworth Council now wants a change in the law to prevent disruption caused by frequent challenges.

Graveney selected half of all its pupils on the basis of ability until August 2000 - the figure is now one third.

Each time attempts are made to change the secondary school's admissions policy, Graveney is obliged to make a detailed response before the adjudicator makes a final decision.

Councillor Malcolm Grimston, cabinet member for education, welcomed the decision but said the process caused "great anxiety among local parents and has been a major distraction for school staff".

He added: "Instead of allowing excellent schools like Graveney to be attacked in this way, ministers should be learning from them."

He called on the Government to lengthen the time limit between challenges to five years and said that scrapping the selection policy would bring a system of "selection by house price, with the best schools reserved for the parents who can afford to buy in the area".

But Labour's education spokesman, Councillor Andy Gibbons, hit back and claimed selection by house price is the consequence of Graveney's current policy.

He said the policy was introduced because "they weren't getting the quality of intake they wanted".

Coun Gibbons added: "Previously it would draw quite a lot from lower socio-economic groups. Now it's got parents who can afford coaching to get their children through the entrance test.

"People want it to be a true community school and to draw from the local area."

The council said 94 per cent of Graveney pupils live within three miles of the school and 75 per cent from within one and a half miles.

The adjudicator, Professor David Newton, ruled that changing the admissions policy would harm the school's standards and would be to "the detriment of all local parents".

A spokesman for the Department for Education said the adjudicator can refuse to consider an objection if it is more or less the same as one made the previous year.