The health secretary has urged the NHS to add fluoride to all water supplies across England in a bid to improve oral health.
Since 2003 local strategic health authorities (SHA) have had the legal power to compel water companies to enrich tap water with fluoride.
However, none have taken up this right and Alan Johnson today announced £32 million of government funding to enable SHAs to consult local people on the case for fluoridation.
The Department of Health (DoH) is in favour of mass fluoridation, pointing to evidence it can reduce tooth decay by 15 per cent among children.
Only ten per cent of England's water supplies are fluoridated at present, mainly in Birmingham and the north-west.
Mr Johnson said today there was a "huge" difference in the dental health of children in Birmingham and nearby Manchester.
He said: "Fluoridation is scientifically supported, it is legal, and it is our policy, but only two or three areas currently have it and we need to go much further in areas where dental health needs to be improved.
"It is an effective and relatively easy way to help address health inequalities - giving children from poorer backgrounds a dental health boost that can last a lifetime, reducing tooth decay and thereby cutting down on the amount of dental work they need in the future."
Critics, however, warn the long-term risks of fluoridation are unclear while there is evidence to show excessive fluoride can discolour teeth.
The National Pure Water Association vigorously opposes fluoridation, arguing it forces the majority of people to take an unproven medication for the benefit of a small minority.
Mr Johnson said he recognised some people have "strong views" about fluoridation, which is why the DoH wants SHAs to put the policy to local consultation.
The department is making £14 million a year available to SHAs over the next three years to enable local consultation and policy implementation.
The Liberal Democrats agreed there was a case for fluoride, but insisted the policy should not be imposed nationally from Whitehall.
Lib Dem health spokesman Norman Lamb said: "Local communities must have the power to decide if and when they want fluoride in their water supplies."
He also raised concerns the government could use the debate to side step the "real issue" of a lack of access to NHS dentistry.
The British Medical Association (BMA) has welcomed the government's stance, saying increased funding is "very good news".
BMA's head of science and ethics Dr Vivienne Nathanson said the fluoridation of water was an "effective public health strategy" for reducing tooth decay.
She added: "Different communities have different needs and it is essential that there is local debate and a democratic process before any final decisions are made."