The Greenwich Judgement was introduced to prevent local authorities favouring their own residents when they offer places at their most popular schools.

The admissions policy has angered parents in Richmond who have been unable to send their daughters to Waldegrave School, the only all-girls school in the borough.

Dr Cable said: "Every year there is anguish among local parents trying unsuccessfully to get their children into our popular schools and their frustration is heightened when children of non-residents do get in, as the law does not allow the council to give residents preference."