A High Court ruling in London has put plans for a development of up to 35 custom built homes on land near the River Wylye at Warminster in disarray.

A judge quashed the outline planning permission for the scheme, meaning Wiltshire Council will have to take a second look at the application.

One of the country’s top judges, Mr Justice Cranston, ruled that Councillor Magnus Macdonald, whose vote carried the decision in favour of granting outline planning permission, should never have been part of the committee considering it, because of his "private interest" as director of an affordable housing company involved in the project. This, said the judge, constituted "apparent bias" which meant that the decision must be quashed.

He said that Coun Macdonald's participation in the decision to grant planning permission for the development at least "gave rise to an appearance of potential bias" as it was plainly in the interests of him and the company of which he is a director, Selwood Housing Association that permission be granted.

While the judge said that this would not be an issue in the great majority of affordable housing applications made to the council, in this case Selwood was "the only provider which had been willing to give assistance on the scheme" and had been named by the applicants for planning permission as their "potential partner" in the development.

Coun Macdonald earns £3,000 per year in his capacity as director of Selwood.

He added: "In all these circumstances it was wrong for Cllr. Macdonald to have participated in the meeting."

Now Lindsay Holdoway, who inherited the site near the River Wylye from his father in 1991, and his company HPH Ltd will have to again persuade the Council to approve plans for a scheme of up to 35 residences, including nine affordable homes.

The scheme attracted strong local opposition, including from a nearby resident who lives on the river about 700m downstream. This resident, named only by the surname Kelton, took the matter to court.

Though the judge rejected claims that the development would have a significant impact on the River Avon special area of conservation due to the risk of contamination of the River Wylye, and that the council had failed to properly assess the environmental impact, he quashed the decision on the apparent bias ground, and ordered the council to reconsider the matter.