A health authority was accused in the High Court today of unlawfully attempting to force through the fluoridation of a city's tap water.
The legal challenge was brought by Southampton resident Geraldine Milner, backed by local campaign groups.
Ms Milner's counsel David Wolfe told a judge that, if the scheme goes ahead, the mother of three teenagers would be left "with no choice but to drink water to which fluoride has been added".
As opponents of fluoridation demonstrated outside the Royal Courts of Justice in London, Mr Wolfe said approximately 195,000 people in Southampton and parts of south-west Hampshire "would have fluoride added to their water whether they liked it or not".
He told Mr Justice Holman this was contrary to Government policy that no new fluoridation schemes should be introduced unless it could be shown that the local population was in favour.
The South Central Strategic Health Authority (SCSHA) used statutory powers to instruct Southern Water, the local water provider, to go ahead with fluoridation in February 2009 to improve dental health.
The controversial decision came after 72% of those who responded to public consultation opposed fluoridation, with just 28% in favour.
An opinion poll commissioned by the SCSHA produced a narrower result, with 38% against the scheme and 32% in favour and 29% "don't knows".
Mr Wolfe accused the SCSHA of failing in its legal obligation to properly assess the cogency of the arguments for and against mass fluoridation.
Mr Wolfe said today's application for judicial review was not about the actual merits and health arguments over fluoridation, which were "not all one way by any means".
It was about the legality of the compulsory scheme, the first of its kind in the UK for 20 years.
Mr Wolfe said: "Four out of five local authorities and three out of four local MPs expressed their opposition within the consultation process."
He added: "Ms Milner is in good company, whether she is right or wrong."
The health authority is opposing Ms Milner's legal challenge.
In a two-day hearing, John Howell QC is arguing on behalf of the SCSHA that the authority was required to make a decision on the merits of the scheme, having taken into account local opposition.
But the authority was not legally bound to give effect to whatever the majority of consultees thought, one way or the other.
James Eadie QC, appearing for Health Secretary Andrew Lansley, is supporting the SCSHA's stance.
Arriving at court today, Ms Milner said her family had no need of fluoride in their water, which the authority particularly wanted to introduce to prevent dental decay in children.
Ms Milner said: "We do not wish to have it.
"What has not been listened to is that there are cheaper, thoroughly researched and proven, effective ways of targeting children who are at risk of dental decay."
The case today was not about the safety of fluoride, but about whether the SCSHA had acted legally in making its decision.
"It is about whether an unelected body have the right to do this when 72% of respondents to the consultation said no.
"It is about Southampton residents' fundamental freedom of choice over their bodies and rights to democracy and justice."
Elizabeth McDonagh, chairman of the National Pure Water Association, which campaigns against fluoridation, described it as a very important case because of its general implications for democracy.
Ms McDonagh said: "Politicians both in Parliament and outside Parliament have said over the years that fluoridation would never be imposed on a community - and yet SCSHA is doing just that after they had a consultation with the public in which 72% of the 10,000 responses from the local community came out against fluoridation."
A phone poll supposed to reflect the views of a mix of the local population also opposed fluoridation, even though by a reduced margin.
"It is absolutely clear, the SCSHA wholly ignored local people's views," said Ms McDonagh.
Stephen Peckham, chairman of Hampshire Against Fluoridation, said there was "huge controversy" over water fluoridation.
He said: "Other countries, including Canada, Ireland and now even the US, are actually lowering the amount of fluoride."
This was because of health concerns, particularly over dental fluorosis, in which tooth enamel was damaged by too much fluoride.
There were other health concerns, although medical sources had conceded not enough was known about either the effectiveness of fluoride, or the safety of fluoride in water.
Mr Peckham added that strategic health authorities were facing abolition, and the SCSHA scheme was likely to be the last one to be permitted by such an authority.
"In just over a year's time it will be up to local authorities to take over these responsibilities," he said.
"Everybody elected democratically in the local area is against it. Local people are against it, but the SCSHA is determined to go ahead.
"The SCSHA has put aside £400,000 to fight their case after already spending over £500,000 on the consultation itself.
"An enormous amount of public money has been spent, but I cannot see there is any value."
The hearing continues tomorrow.