A judicial review has been launched into an “unlawful” planning decision for a residential extension and annexe in Steeple Morden.

South Cambs District Council has formally apologised for the error, which came only days after the High Court quashed the council’s previous approval for planning permission on the Craft Way site.

The most recent claim for judicial review is being brought by the Fews Lane Consortium, a community action group that represents the interests of local residents in the planning process.

In a notice published on the council’s website announced that a public consultation on the planning process is being carried out, and that the public is invited to comment until December 11.

However, despite the consultation period not having ended, the council had already issued a decision approving the development – which was dated November 13, and signed by the council’s joint director of planning and economic development Stephen Kelly.

In addition, a six-page officer’s report was also published on the council’s website on the same day, detailing the council’s reasons for granting planning permission.

Earlier this year, the council issued planning permission for the Craft Way site, only to have it quashed in the High Court after the council approved the wrong plans for the development. According to the Fews Lane Consortium, the council had also failed to lawfully delegate its authority to decide the application to the officer who took the decision.

Daniel Fulton, who is leading the legal action against the council, said it was not the first time the council had issues planning decisions in the middle of consultation periods – citing an example from Longstanton in May this year.

He said: “As if facing a second judicial review on one planning application wasn’t damning enough for the council, it appears that the district council attempted to hide its illegal decision by deleting its decision notice from the public planning register on the council’s website.

“The fact that the council not only made an illegal planning decision but then tried to cover it up by deleting the planning permission from the public register calls into question the integrity of the entire council as an organisation and in particular the professional judgment and integrity of officers at the council’s planning service.”

Screenshots taken by a concerned local resident indicate that the decision notice, which was published on the council’s website at 12.07pm on November 13, had been deleted by 12.44pm.

According to Mr Fulton, once a decision notice has been issued, it is legally binding even if the council tries to hide the decision notice by deleting it from the council’s official planning register.

He also said there were “very serious problems” at the Greater Cambridgeshire Planning Service – which serves both South Cambs District Council and Cambridge City Council.

The previous planning decision was quashed by Cllr Aidan Van de Weyer, deputy leader of the council, which allowed the second decision to be issued.

The Steeple Morden planning error follows another error in Great Abington, in which a formal decision notice was issued without several accompanying necessary conditions.

Since then the council has apologised and started investigations into both errors. According to the council, the Steeple Morden decision was due to human error, as it was issued without the relevant authorisation when the wrong box was ticked on the planning computer system. To avoid further delay, the applicant has been invited to submit a new planning application for their proposed extension and annexe.

Council leader Cllr Bridget Smith said: “We are very sorry. We’ve spoken to the applicants and their planning agents in both of these cases, and have written to them, to apologise.

“Our Internal Audit Team is already investigating what has happened. We’ll be reviewing the recommendations from their report as well as looking at how we can change our processes to try and further limit the possibilities for human error.

“Unfortunately, we have no option but to go to the High Court to rescind these incorrect permissions and this is why the lead cabinet member for planning has already started this process.

“We are taking this very seriously and I want to apologise again.”