Montgomery County legislators on Tuesday are expected to approve an amended version of a countywide ambulance fee that was struck down by referendum in 2010.

The fee would be charged to patients for ambulance service, 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. County officials stress county residents would neither see a bill nor incur any 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 the voters have already decided.

After dueling campaigns involving hundreds of volunteer and career fire and rescue personnel, the original bill in 2010 became the first and only law to be struck by referendum. To bolster county revenue for fire and rescue services, County Executive Isiah Leggett (D) proposed a similar bill last month and then offered amendments earlier this week to gain council support.

On Friday, the county council’s public safety committee voted 2-1 not to recommend the legislation. It is expected to be presented to the full County Council on Tuesday.

Committee chair Phil Andrews (D-Gaithersburg-Rockville) and Council President Roger Berliner (D-Potomac-Bethesda), who sits on the committee, both voted against the legislation two years ago and against the bill at the committee meeting Friday.

Still, six council members have pledged to vote for the bill with Leggett’s amendments. Council members Marc Elrich (D-At Large), who sits on the committee, and Nancy Floreen (D-At Large) supported the bill two years ago.

Two former opponents, Valerie Ervin (D-Eastern County) and Nancy Navarro (D-Midcounty), said the amendments improve and clarify the bill. They include the creation of a patient advocate to provide customer service and semiannual reporting on the program.

Craig Rice (D-Upcounty) and Hans Riemer (D-At Large), who both support the bill, were not on the County Council during the last vote.

George L. Leventhal (D-At Large), who supported the fee two years ago, proposed an alternative this week: a charter amendment that would lift the cap on a tax that would support fire and rescue services. In an interview, Leventhal said he initially supported the new bill but is now not sure how he will vote.

“I don’t see what in the political dynamic has changed that would make a referendum on this issue [lead to] a different outcome,” he said. “The voters thought it was a bad idea. What has changed?”

Other amendments are also being considered. On Friday, Elrich proposed one to provide additional financial support for volunteer firefighters. Andrews is working on an amendment to prevent county funding to be used for a referendum campaign.

In an interview Friday, Eric N. Bernard, executive director of Montgomery County Volunteer Fire Association, declined to say whether his organization would bring the bill to referendum. He said he hopes that the council members “respect the voters” on Tuesday.

Leggett did not immediately respond to a request for comment on Friday. County spokesman Patrick Lacefield declined to comment.