A councillor says “serious questions” need to be asked after an unpopular phone mast was allowed to be put up because the council submitted its objection a day late.

Mobile phone company EE was accused of illegally constructing a new mast in Allum Lane, close to Elstree & Borehamwood station, in early December.

But it insisted it had done everything by the book after submitting its application to Hertsmere Borough Council on August 15.

In planning law, telecommunications applications still need planning consent, but if no comments are made within 56 days the applicant is free to go ahead.

Hertsmere Council refused permission but issued its decision on October 10 – 57 days after the application – meaning the mast could legally be put up.

Cllr Jeremy Newmark, the leader of Hertsmere’s opposition Labour group, says “serious questions” should be asked.

EE said the mast was needed to boost signal along the railway line, and the mast has been put up between Lodge Avenue and Deacons Hill Road, Borehamwood.

But Hertsmere Council said the mast’s size and height would make it “highly visual and unduly obtrusive”.

People living nearby were opposed to the mast and one wrote to Hertsmere MP Oliver Dowden, saying it was “too close” to homes.

The council has apologised for issuing the notice a day late but says officers believe that had it refused the application, EE would have been successful on appeal.

Cllr Harvey Cohen, who is responsible for planning, at the council said: “Our head of planning has reviewed this case and found that had the council issued a refusal notice within the required time limits, any appeal against that decision would have had good prospects of success.

“However, we do acknowledge that the refusal notice should have been issued in time to be binding and we are sorry that this did not happen in this case. Our administration practices have been reviewed following this case to ensure that decision notices are issued on time in all cases.”

EE said it went ahead with development after writing to the council with its intentions to construct the mast, after the 56-day period passed, and still received no response.

A spokesman added: “We’ve proceeded to build the site with the necessary planning permission in place and we always follow all necessary steps and best practice when applying for planning permission to make sure we keep communities connected.”