Andy Burnham, the new Health Secretary, yesterday urged health service managers to press ahead with the controversial fluoridation of water supplies.

Speaking at the NHS Confederation annual conference, Mr Burnham, an enthusiast for fluoridation, said: “I feel we’ve been too timid at times on the public health agenda. So let’s press ahead with water fluoridation, given the clear evidence that it can improve children’s dental health.”

Mr Burnham stepped down yesterday as honorary vice-president of the British Fluoridation Society after inquiries by The Times. He cited his desire not to carry a perceived conflict of interests into the fluoridation debate.

Putting fluoride in water supplies, to protect teeth from decay by toughening their surface, remains a divisive issue. Opponents question the ethics of “mass medicating” the population and the efficacy of such a measure.

Fluoride is added to water drunk by 5.5 million people in England — a ninth of its population — mainly in Birmingham, the West Midlands and parts of the North East. Another 500,000 people have naturally occurring fluoridated water at equivalent levels, in scattered areas mainly down the East Coast. The Government is keen to fluoridate the water supply in areas with high levels of dental decay.

Successive governments and health secretaries have supported greater fluoridation, [particularly in deprived areas where nutrition is poorest and oral health discipline is weakest. Moves to introduce it more widely stalled for 30 years after local authorities lost their public health powers in 1974 and water companies were privatised.

A change to the law in 2003, em- powering health authorities to make water companies act, allowed the first new fluoridation scheme in Hampshire this year, despite strong opposition. Authorities in the North West, Derbyshire, Bristol and Kirklees in West Yorkshire are thought to be among those preparing to introduce similar proposals.

The Scottish government decided five years ago that it did not want local authorities to have such powers and the Isle of Man dropped the idea last summer.

Professor Michael Lennon, of the School of Clinical Dentistry at the University of Sheffield and chairman of the British Fluoridation Society, welcomed Mr Burnham’s support for more fluoridation. He said that an estimated 30,000 children needing dental care under general anaesthetic every year, at a cost of £1,000 each, was evidence enough of the need for strong action.

“We have long been concerned about the very high level of disease in young children and the need for treatment under general anaesthetic,” he said. “It is very distressing for children and their families.”

The National Pure Water Association said that there was no strong evidence to support the safety or efficacy of fluoridation. “Fluoridation proponents are therefore promoting quack medicine,” a spokesman said. “This medical intervention is currently being carried out by UK water companies without the individual consent of their customers. Water companies are doing to their customers what would attract a charge of assault and battery if a doctor did the same to a patient.”

The Department of Health said there was no question of central government imposing fluoridation. “Decisions should be taken locally following consultations,” a spokesman said.

He added that Mr Burnham had decided to step down from the fluoridation society with immediate effect “as he appreciates that there could be a perceived conflict of interest”.