Campaigners opposed to the government’s decision to approve a grammar school annexe in Sevenoaks have put a legal challenge on hold.

The campaign group Comprehensive Future was expected to announce whether it would be pushing forward with a judicial review of the decision this week, but members have been unable to determine whether the plans are legal because of difficulty obtaining information.

In October last year, education secretary Nicky Morgan gave the green light for the annexe of the Weald of Kent Grammar School in Tonbridge to be built.

The government has insisted that the approval is legal as they say it is not a new school in Sevenoaks, but instead an expansion of the existing girls’ grammar school in Tonbridge, located 10 miles away from the proposed school.

A spokesperson for Comprehensive Future said: “In the past few months, Comprehensive Future has requested information from the government, Kent County Council and the school in order to test the legal basis of this claim.

“Information has often not been forthcoming or has been unaccountably delayed.

“Those plans that Comprehensive Future has been allowed to see appear to be highly impracticable and are unlikely to be sustained over the long term but the government has forbidden us to discuss these publicly.”

The group said it intends to keep a close eye on the development of the school and, in particular, it will be scrutinising details of the school’s plans when published in the funding agreement.

The spokesperson added: “We believe we are much more likely to win any legal argument when all the information pertaining to the day-to-day running of the school is out in the open. In the meantime, we urgently call on the government, council and school to release all proposals relating to the school’s future.

“There now needs to be robust public discussion about whether Sevenoaks really is an annexe of an existing school or whether the current plans are, as we believe, a concerted and blatantly political attempt to get round the law.”

The school is due to open in September 2017 after a long campaign by parents who said pupils had to travel long distances to take up grammar school places. Andrew Shilling, of the Sevenoaks Grammar School Campaign, called it “excellent news”.

He added: “Whilst today’s news is most welcome, excluding boys from the Sevenoaks grammar annexe is very unfortunate. In recent years Sevenoaks boys have found it harder to access grammar school places than Sevenoaks girls, and we hope that a boys’ grammar school will now come forward to sponsor a boys’ annexe.”

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