Two animal welfare groups are challenging the government's backing of a £32m research laboratory which will use monkeys in research on Alzheimer's, Parkinson's and other incurable diseases.

Lawyers for Animal Aid and the National Anti-Vivisection Society have lodged an appeal against the deputy prime minister, John Prescott's approval of the project drawn up by Cambridge University.

Judges will be asked to set aside Mr Prescott's decision to overrule his own planning inspector by backing the lab on green belt land near Girton, Cambridge. The appeal describes the minister's action as "perverse and unreasonable" and based on minimal fact and flawed information.

The societies will also accuse the prime minister and the science minister, Lord Sainsbury, of prejudicing the outcome of the planning process by speaking publicly in favour of the labs while the question was under official review.

Scientists defended the proposal at the planning inquiry a year ago. They said experiments carried out on monkeys would be crucial for potential breakthroughs in treating some of the most-feared incurable diseases.

The labs were opposed by South Cambridgeshire district council, whose planners had earlier turned the scheme down twice. Cambridge police, who have had to deal with attacks on existing laboratories in the area, were also against the development.

The inspector, Stuart Nixon, ruled that the university had failed to show that there was a national need for the work due to be done in the labs. He was overruled by Mr Prescott in a statement issued at the end of November.

Andrew Tyler, director of Animal Aid, said: "John Prescott has dismissed the well-founded case of his own inspector and given the go-ahead, so this challenge has a solid base in morality, science and the democratic process.

"There is a great deal of opposition from the public and politicians and even within the university because it is expensive and controversial."