A study by Public Health England last year found more than a third of five-year-old children in the Darlington area had several decayed teeth by the time they started school.

Supporters of fluoridation say it is the most cost-effective public health measure that could be introduced to improve oral health in Darlington.

However, suggestions that fluoride could be added to the water supply in the town has attracted condemnation from campaigners, who claim to do so would infringe their human rights.

Darlington resident Alan Hall said fluoride’s toxicity rating was between lead and arsenic and therefore was a “poison”.