Education secretary Michael Gove is under renewed pressure to give the green light to plans for a "new" grammar school in Kent amid growing concerns he is stalling.

Campaigners say they are worried that any delay in the decision will derail the timetable for the annexe in Sevenoaks to be built.

Mr Gove has told Sevenoaks MP Michael Fallon government lawyers are assessing the legality of the scheme.

The plan is for a new annexe on the former Wildernesse school site to address a shortage of selective school places in Sevenoaks.

Two rival bids have been submitted to run the annexe: one from the Valley Invicta Academies Trust in Maidstone and one the Weald of Kent Grammar School.

Kent County Council, which is backing the Invicta application, submitted plans for the annexe in the summer. It believes the scheme would ease the pressure on places.

About 1,100 children from the area travel to grammar schools in Tonbridge and Tunbridge Wells.

Mr Gove told Mr Fallon in a letter: "Primary legislation prohibits the introduction of new selective schools and we must judge the proposals carefully to test whether they represent new schools or expansions."

In a statement, a Department for Education spokesman said: "We believe strongly that good schools - including grammars - should be able to expand.

"The law prohibits the establishment of any new selective school. We are currently assessing proposals for a site in Sevenoaks. No decision has been made."

Sarah Shilling, who led the parents' campaign for a new annexe, said: "What is worrying is the length of time it is taking, which could set it back for a year."

Meanwhile, it has emerged KCC paid lawyers £6,150 for advice about the legality of the scheme. The figure was disclosed in response to a Freedom of Information request made by the KM Group.