Killjoy officials are trying to force a family to tear down a teenage boy's beloved treehouse.
Neil and Cheryl Tolley, of Church Lane, Pinner, said their son James, 13, enjoyed using the little raised cabin and verandah as a den with his friend and climbing the rope ladders.
But Harrow Council has refused planning permission for the wooden hut, even though Mr Tolley maintains it cannot be seen from anywhere but his own back garden and does not overlook neighbours.
Mr Tolley said: "My son loves it. He's going to be very upset.
"It's got completely out of hand. I think the council has been spiteful."
The Tolleys' gardener built the wooden hut with stairs in June 2006 and James used it for nine months without problem until a complaint sparked a Harrow Council investigation.
Council officers confirmed in March last year retrospective planning permission was required.
But when the family applied, councillors refused permission, rendering James' tree house illegal and paving the way for forceful demolition.
A council report said: "The treehouse, by reason of excessive size, bulk, unacceptable design and siting, is an inappropriate form of development in this location, is unduly obtrusive and overbearing and results in perceived overlooking of neighbouring occupiers."
The hut still stands, however, because Mr Tolley has appealed to the independent Planning Inspectorate.
He said: "I would have never allowed my son to disturb the quality of neighbours' lives.
"He and his friends are not noisy, we've never had any complaints from neighbours and, furthermore, you can't even see the structure. It's hidden by foliage.
"I felt I ought to appeal out of principle. I feel that it's sad that the council has money to waste. They must have more important things to do."
Councillor Marilyn Ashton (Conservative), portfolio holder for planning, development and enterprise, said: "This is not a treehouse, as one would imagine a treehouse to be. It is a substantial wooden structure on a platform which is contrary to Harrow Council's policies and, in particular, Conservation Area policy. It overlooks a neighbouring property and has prompted objections from a nearby resident.
"Harrow Council has absolutely nothing against treehouses per se, but the description of a treehouse should not be used as a cover to erect large buildings, in Conservation Areas which cause overlooking, damage the environment and character of the area."