The long-running battle over plans to add fluoride to domestic water supplies in and around Southampton could be heading for a showdown in court.

Hampshire councils and the Government’s health agency are at odds over the controversial scheme.

Plans to put fluoride into the tap water of 200,000 residents in parts of Southampton, Eastleigh, Totton, Netley and Rownhams were given the go-ahead in 2009.

The plans, which were initiated by the South Central Strategic Health Authority (SHA), sparked fierce resistance from campaigners.

They say there are unanswered questions over the health issues around drinking fluoride in tap water and that the people affected should be the ones to decide whether it is introduced or not.

The SHA, which was axed by the Government last year, had always argued introducing it would benefit public health and its successor organisation Public Health England (PHE) had vowed to plough on with the plans.

But following legal advice, Hampshire County Council leader Roy Perry and Southampton City Council boss Simon Letts believe the scheme no longer exists due to the SHA’s failure to hand over vital documents to its sucessor the PHE.

They have been waiting for five months to find out what the Government and PHE’s appraisal of the situation was.

This week, PHE chiefs announced that although the paperwork was not completed, they still believed the fluoridation scheme existed.

Now, with neither side willing to budge, they are set for a legal battle.

Southampton City Council leader, Simon Letts, said: “There are two legal views about fluoridation. Until those legal points are tested in a court, we will be no further forward.”

He said fluoridation would not go ahead without a court ruling “At the very least, this has given us time to assess all of our options and even if a court eventually rules against us, I have already told PHE that a referendum should be held to determine whether it happens or not,” he said.

A spokesman for PHE would not confirm the threat of legal action, saying instead: “PHE is committed to working with partners on the key issue of oral health improvement, including the role of water fluoridation.

“PHE continues to give full and careful consideration to all the relevant factors relating to water fluoridation in Southampton and SW Hampshire and is still considering its position in relation to the scheme.”