The New South Wales opposition has tabled legislation it says would end the “anti-fluoridation circus” by forcing local authorities to add fluoride to water supplies.

NSW Labor’s bill, which would take away local authorities’ veto over fluoride, follows a series of decisions to ban the substance.

This week, Lismore council voted to reverse a ban on fluoride after a heated public meeting at which an anti-fluoride protester threatened NSW’s chief medical officer Dr Kerry Chant, saying: “I have friends in Syria, do you know of sarin gas?”

Opposition health spokesman Andrew McDonald said fluoride, which is widely backed by scientists as a safe way to protect teeth, was “one of the most cost-effective health interventions ever used”.

However, there are about 300,000 people in NSW who do not have access to fluoridated water.

“Every day without fluoride puts a child at risk of preventable dental decay,” McDonald told the NSW parliament. “It’s time for the NSW government to step in and take control. For many of these children the damage has already been done. It’s time for this anti-fluoridation circus to end.”

The NSW government said it would consider the bill and stressed it was committed to improving dental health in the state.

The NSW health minister, Jillian Skinner, told Guardian Australia in a statement: “I remain in talks with NSW Health regarding options to increase fluoridation of water in NSW.

“I will raise the issue in cabinet on Monday, when the opposition bill will also be discussed.”