It is "difficult" to see how a fire brigade can make further cuts without potentially increasing the risk to local communities, public spending watchdogs have warned.
The Accounts Commission said that Fife Fire and Rescue Service (FFRS) had already made "significant savings" but now faced the need to make further reductions to its budget.
But it said: "It is difficult to see how further savings can be achieved without the potential for some increase in community risks."
The warning came in a report the Commission published about the brigade on Thursday.
The service is funded by Fife Council and the report pointed out that, as a result, it "needs to compete directly with other services within Fife Council for financial resources".
The Accounts Commission said, so far, FFRS had managed to maintain standards at the same time as reducing the size of its workforce.
However, it added the service "now faces significant challenges with the need to make further savings of 4% - 4.5% in each of the following three years".
The report went on: "It now faces a specific challenge to maintain its standard crewing levels for all emergency responses."
FFRS had considered making redundancies but avoided this by transferring 15 firefighters to neighbouring services.
However, the report said that unlike other fire brigades in Scotland Fife "often has to reduce crewing levels below its standard levels".
It added: "Even with its current workforce, it is a challenge to maintain its standard crewing levels on fire appliances."
The report warned: "The difficulties of balancing the need for financial savings with community safety look to be even more challenging over next year.
"FFRS is now seeking to identify further savings for 2012-13, which is likely to involve further reductions in its workforce and potential changes in duty rotas."
Claire Baker, Labour MSP for Mid Scotland and Fife, said the Fire Brigades Union (FBU) had been warning that "Fife Council's decision to squeeze budgets will impact on community safety".
Ms Baker said she was raising the issue with ministers and added: "The SNP Government has since acknowledged that there is a problem in Fife and yet they won't step in with a solution.
"Ministers must now address the FBU's concerns before the staffing situation gets any worse and lives are put at risk."
Neil McFarlane, chief fire officer for Fife Fire and Rescue Service, said: "As we move forward in the development of a national fire and rescue service, we in Fife Fire and Rescue Service will continue to do all we can to ensure that the people living and working within our communities receive a high quality service.
"It is important that the right people, with the right skills, are in the right place, at the right time, thereby delivering added value to society and achieving outcomes that can be measured in support of our overall aim of 'making our communities safe'."