The Montgomery County Volunteer Fire-Rescue Association announced Monday that it is dropping its opposition to a controversial ambulance fee, meaning that patients could be charged for a ride to the hospital as early as January.

The fee, which would range between $300 to $800, was initially opposed by the volunteer firefighters because of fears that it would deter some residents from calling 911.

As they did two years ago, when they helped kill a similar proposal, the volunteer firefighters mounted a campaign recently to collect signatures to put the measure to a vote in November. But at a news conference on Monday, the fire-rescue association said it had struck a deal with the county, that would give the volunteers 15 percent of the revenue generated by the fee, which is estimated at $18 million a year and would likely grow over time.

Eric N. Bernard, the association’s executive director, said he will monitor ambulance calls to make sure they don’t drop because of the fee.

Bernard said the association had collected more than 11,000 signatures but stopped gathering them about two weeks ago. He said the volunteers were “getting fatigued.”

“Our concentration is on fire and rescue, not on collecting signatures,” he said.

The fee, which was expected to be one of three controversial issues in the November ballot, will help pay for fire and rescue equipment and personnel costs. County officials said that in nearly all cases, private insurance companies, Medicare and Medicaid would cover the cost of ambulance service, which would vary depending on the distance and urgency of the trip. County officials have said they would ensure that residents don’t pay out-of-pocket costs, but there were still some out-of-county patients who would pay.

At the news conference, County Executive Isiah Leggett (D) said he would try to prevent even those patients from having to pay. But there are legal obstacles, and it remains unclear whether they will be able to do so, county officials said.

Bernard said that if the county doesn’t overcome the legal hurdles, his group may work with hospitals and nonprofit organizations to create a fund to reimburse those patients.

The fee has had a rocky path. It was initially approved by the county council in 2010 as a way to generate additional revenue. The firefighters were able to put it to a vote, and residents knocked down the measure that same year. Undeterred, the council passed an amended version of fee again in May.

Meanwhile, longtime Republican activist Robin Ficker submitted 14,500 signatures for a referendum on the controversial county energy tax. An unpopular increase to the levy was set to expire this year, but in May the county council voted to extend the vast majority of the hike.

On Monday, Ficker visited Leggett’s office with two boxes containing 3,000 pages of petition documents. If approved by the County Board of Elections, the petition would allow voters to make the energy tax harder to increase.

Ficker’s measure would require a unanimous vote by the county council to increase the tax above the rate of inflation.

“They broke their promise to voters,” said Ficker, who in 2008 got a similar measure approved involving the county property tax.

Also, the county police union is trying to repeal a law that curtails its collective bargaining rights. Enacted this summer, the law prevents the union from negotiating on day-to-day duties, such as checking e-mail.

The union, the Fraternal Order of Police Lodge 35, has hired outside consultants to collect signatures to challenge the law. County elections officials certified the petition in November, but the county quickly sued to block it. In June, a county judge struck down the petition, saying it contained inaccurate information.

On Thursday, union lawyers will argue before the Maryland Court of Appeals to reinstate the petition.

The legal action has been costly. County spokeswoman Donna Bigler said in an e-mail that Montgomery has spent $201,000 in legal fees.