A controversial treehouse that was put at risk by a town hall blunder has been saved – to the delight of supporters including actor Rupert Graves and his family.

Council bosses could have been forced to take down the 22ft play structure in Arundel Square after they forgot to apply for permission from their own planning department before it was erected in March.

But it will now stay in place in the middle of the Holloway green space after a planning committee gave retrospective consent last Thursday.

The meeting at Islington Town Hall was attended by Sherlock and A Room with a View star Graves, 49, who lives in Arundel Square with wife Susie and their five children.

Afterwards he said: “It’s just really good fun and it’s very important that children have small areas of territory that they completely own.

“It’s unusual for kids in an urban environment to have a play a structure which is a little bit dangerous and entirely their own world, with hardly any old people interfering in it.

‘‘It’s something that becomes their space and that’s really nice.”

The treehouse had been mysteriously vandalised in September in what appeared to be a deliberate act of sabotage, involving specialist tools and forethought.

A petition in support of the treehouse gathered 525 signatures while 74 people wrote to the council in favour – but some residents were not so taken.

Seventeen people penned letters of objection, complaining about the height, appearance and loss of privacy, and saying that it attracts anti-social and noisy teenagers.

At the meeting, Olivia Cole raised concerns about new flats in Westbourne Road being overlooked. She said: “I’m very enthusiastic about the development of the square in general, but when you buy a flat on the second floor you are not expecting to be overlooked. I think it’s excessively high and it was a shock when it was put up.”

Ms Cole wanted the council to lower or screen the top platform, but committee member Cllr Robert Khan said her concerns could not be taken into account because her flat is too far from the treehouse.