The Montgomery County Council approved a countywide ambulance fee Tuesday, reviving the only county law to be struck down by referendum, and also overrode the first and only veto by County Executive Isiah Leggett (D).

Patients would be charged the fee for ambulance service, ranging from $300 to $800, but it would be paid for by health insurance in most situations. People without health insurance and people below a certain income threshold would be exempt from the fee. Officials stress that county residents would neither see a bill nor incur out-of-pocket expenses.

But volunteer firefighter groups say they oppose the fee, partly because it would make residents hesitant to call for assistance. They added that county officials should not resurrect an issue on which voters have decided.

Some county officials expect volunteer firefighter groups to start another referendum campaign. Eric N. Bernard, executive director of the Montgomery County Volunteer Fire Rescue ­Association, said the volunteer fire departments will vote on pushing the referendum at a meeting Thursday night.

Two years ago, the county spent more than $13,000 to create promotional materials and pay staff overtime costs to post banners during the referendum campaign, according to county spokesman Patrick Lacefield. Margie Roher, a spokeswoman for the county’s board of elections, could not immediately provide the cost of the referendum election on Tuesday.

By enacting the fee, the county again joins the majority of local jurisdictions that have similar fees. Prince George’s, Fairfax and Prince William counties have them, while Calvert, Loudoun and Howard counties do not.

The County Council originally approved the fee in 2010 but it was repealed later that year. To bolster county revenue, Leggett proposed a similar bill last month, then offered amendments last week to gain council support.

The amended bill creates a patient advocate, with $76,000 in salary and benefits, to provide customer service, and requires semiannual reporting on the program. Council supporters say the changes make the bill materially different from the original legislation. Opponents disagree.

“The bill is essentially the same,” said council member Phil Andrews (D-Gaithersburg-Rockville), a strong opponent of the fee. “Governments need the revenue, but they need the trust of the people they represent more.”

But council member Marc Elrich (D-At Large) said voters were misled during the referendum campaign two years ago, and council member Valerie Ervin (D-Eastern County) said the volunteer firefighters “participated in a massive fear campaign.”

Council members on both sides of the issue have switched positions over the past few weeks. Two former opponents, Ervin and Nancy Navarro (D-Eastern County), said the amendments improve and clarify the bill. George L. Leventhal (D-At Large), a former supporter, said he does not believe the public’s mood has changed. He voted against the bill.

Leventhal said he would propose a charter amendment to remove the cap on the fire tax and ensure that its revenues would go to fire and rescue services. Marcine Goodloe, president of the Montgomery County Volunteer Fire Rescue Association, said her group would support the tax change.

Legislators also voted Tuesday to prevent funds from being used to implement the fee before Jan. 1, when the results of any referendum on the bill are final. Assistant Chief Administrative Officer Kathleen Boucher said that until then, the county will work on tasks that don’t require additional revenue, such as recruitment for the patient advocate.

Earlier in the day, the County Council overrode Leggett’s veto, which lasted for less than 18 hours. In a council memo sent shortly before 5 p.m. Monday, Leggett announced his decision to strike down a bill that would increase legislative oversight over his economic development decisions.

The bill generally would allow legislators to prevent county officials from selling lucrative county properties. The legislation was part of a slew of bills the council considered to boost local economic development.

Leventhal said Monday that the council members were working overnight to get the override vote scheduled for Tuesday. They succeeded, voting at 10:30 a.m. “There should be a system of checks and balances in place,” he said.

Leggett said in an interview that he did not believe the veto would last, but he said he wanted to be on the record about his opposition to the bill.