Brenda Gowland, 52, and her husband Tony, 47, foster children who have various problems.

A 10-year-old lad they are looking after is not allowed out unsupervised, so they have adapted their house and garden in Albany, Washington, to provide a suitable environment.

But by moving a fence they have fallen foul of planning rules and could be forced to move it back – leaving them angry and out of pocket.

It was suggested to them that they should improve the exit route from the back of the house, which was bordered by a six-foot fence in front of a tangle of briar bushes and a footpath.

Brenda said when she asked gentoo – which removed the bushes for £140 – the organisation said there would be no problem with relocating the fence nearer the footpath, on land they believe they own.

So they were shocked to be contacted by Sunderland Council planners, saying they would need permission for a change of use of open space to a private garden.

"We thought we were okay," said Brenda. "We weren't building anything – we were just moving a fence."

She said they have been left with the costly options of putting in a retrospective application for planning permission – which they have been told is unlikely to be granted – or moving the fence back.

Brenda said she had already had to sell a car to pay to make their home suitable for the foster child and they did not know what to do next.

"Labour are saying they are going to make planning easier," she said. "Or are they saying every child doesn't matter?"

The council said complaints had been received from the public about "the enclosure of land comprising part of a public amenity area".

Phil Barrett, director of development and regeneration, said: "The new fence juts out obtrusively and the removal of the shrubs has spoiled the appearance of the area.

"On balance, the development is considered to be unacceptable and detrimental to the otherwise open and pleasant surroundings."

He said the family had been approached to submit a retrospective application to be considered openly through the normal channels.

However, he said they had declined to do so despite further requests, and the authority had no option but to take enforcement action.

He added: "The council is not aware of any special circumstances, in planning terms, which require the extension of the garden to improve the security of the property."