Officials of the union that represents the District's ambulance workers said yesterday that political infighting in the fire department and office of the public health commissioner has slowed improvements to emergency ambulance service, an allegation that city and fire officials disputed.

Frank Fishburn, newly elected president of the American Federation of Government Employees Local 3721, also said at a news conference that emergency medical technicians, paramedics and their union representative have been "excluded from helping to solve" problems.

Between September and March, there were eight reported incidents in which ambulances were slow to reach people who later died. Fire department officials denied any link between the delays and the deaths, but in several of those cases, disciplined dispatchers or ambulance workers.

Mayor Marion Barry has made improving the ambulance service a top priority, including seeking a nationally known medical professional to head the service.

"The idea that there is infighting between the fire department and the office of the commissioner of public health is patently ridiculous -- Dr. {Reed V.} Tuckson does not want the service," City Administrator Thomas M. Downs said yesterday.

Downs and other officials pointed to improvements in the emergency medical service in the past two months, including a decrease from 10 minutes to seven in average ambulance response time and a rise in the quality of emergency medical care under increased monitoring.

Downs said the union officials' complaints indicate "their level of frustration" because of increased scrutiny. "It means that we have to pay a lot more attention to what they're saying even though everything they're saying is not true," Downs said. "In the two things that the public cares about -- response time and quality of care rendered -- we've made a lot of gains."

Fishburn said that Downs had missed by one month his own deadline to appoint a civilian head of the ambulance branch, which now is run by a deputy fire chief, and had not informed Local 3721 of what qualifications the city is seeking in a candidate.

Downs countered that city and fire officials have taken more time to interview civilian candidates nationwide in hopes of hiring the best candidate.

Tuckson, who since March has watched over the troubled 911 emergency ambulance service, said his office and fire department officials, who operate the ambulance service, are meeting daily and working together smoothly after overcoming some initial tension. He said that for the first time representatives from the firefighters, dispatchers and ambulance workers unions had been appointed as voting members to the panel that oversees ambulance service improvements.

"I feel very confident that the process is working extremely well and it would be inaccurate to say otherwise," Tuckson said. But William Jones, executive board member and treasurer of Local 3721, said: "I sure would like to have Dr. Tuckson come out on my medic unit with me and show me where those changes have occurred. I see men and women every day who have been working in this system five, six years saying, 'Nothing's changed and I'm tired.' "