The company behind the 400-home development in Long Ditton made a planning agreement with Elmbridge Council to invest in the infrastructure once 80 per cent of the site was occupied.

But only 30 per cent of homes are filled, although many more have been sold, and a St James spokesman estimates that the trigger point to release the money will come next year.

Tory councillors have called on St James to give some of the money now for traffic studies, because they say Surbiton is under increasing strain from the new families on the site.

Coun Dennis De Lord highlighted the junction of Balaclava Road and Brighton Road as needing special attention, because pedestrians have too little time to cross the road.

But a St James spokesman said that there was no point doing any traffic studies before the 80 per cent mark because such figures would not be accurate until the site was nearly fully occupied.