Overtime is "propping up" frontline policing in Devon and Cornwall, with officers working "excessive" hours and unable to take leave, it has been warned.
The Police Federation, which represents rank-and-file officers, said the problem was "endemic" within Devon and Cornwall.
Branch chairman Sergeant Nigel Rabbitts also revealed they had taken the rare step of formally raising their concerns in writing to Chief Constable Shaun Sawyer.
The move emerged after new figures showed overtime payments to officers totalled some £4.7 million in 2012/13 – almost exactly the same as the previous 12 months, when the force had some 200 more officers.
"There are fewer officers doing more overtime," Sgt Rabbitts said. "Overtime is being used to supplement for a lack of officers and trying to keep the service going, particularly on the front line.
"We are concerned about the welfare issue of people working excessive hours and coming to work tired. They are also struggling to take time off that they are entitled to. We are looking for a solution and pushing the force very hard for a solution, very quickly."
After a stream of complaints from officers, Sgt Rabbitts said they had officially raised the matter with Mr Sawyer earlier this month through the Joint Negotiations Consultative Committee – a statutory quarterly meeting between staff associations and the Chief Constable.
Sgt Rabbitts confirmed there was no timescale for the chief constable to respond. He said the final recourse was to report the matter to the Health and Safety Executive.
Officers have come under increasing strain since the 2010 Comprehensive Spending Review resulted in the force having to save £51 million by 2015 – a move which has seen it lose 400 officers and 500 staff.
Only a 2% rise in council tax imposed by Police and Crime Commissioner Tony Hogg this year saved police officer numbers from dipping to just over 2,800 – a level last seen in the 1980s.
After moving to its "blueprint" model to cope with the cuts in May 2010, the force is now considering another reorganisation.
"The force is trying to move to a new operating model that some think is going to be a panacea to all our problems," Sgt Rabbitts added.
"Unfortunately it isn't, because there still aren't enough people to do what's required."
Only police constables and sergeants, who can be ordered to work additional hours, are eligible for overtime.
It has to be approved by senior officers, although the first half-hour, if unplanned, is worked for nothing. Casual overtime is paid at time-and-a-third while officers get double-time for working bank holidays.
Responding to a Freedom of Information Act request, Devon and Cornwall Police said it spent £4,746,331 on overtime in 2012/13 – marginally up on the £4.7 million outlaid in 2011/12.
Between March 2011 and March 2013, the number of police officers within Devon and Cornwall Police has dropped from 3,436 to 3,082, according to Home Office figures.
Deputy Chief Constable David Zinzan said: "We have just experienced our busiest summer for a number of years. During peak demands such as this we may ask staff to cancel annual leave, however we endeavour to approve leave where possible.
"As our communities would rightly expect, where there is risk to the public, we will ask officers to change their annual leave. This only happens when there is a real operational need.
"The Police Federation and Superintendents' Association have been invited to work with us on this piece of work and this is being carried out now to ensure we have the right numbers of officers, in the right place at the right time.
"I would like to pay tribute to the flexible attitude displayed by my officers and staff. They put the public first and I am very grateful for all that they do, often in very difficult and demanding circumstances."