Senior police officers are planning to cull thousands of injured officers as part of a cost-cutting drive.
Under plans being drawn up by the Association of Chief Police Officers (Acpo), between 14,000 and 18,000 officers whose injuries mean they are no longer able to work on the front line would be offered severance packages.
The Police Federation, which represents 126,000 frontline officers, and the National Disabled Police Association (NDPA) say that any plan to force out injured officers could fall foul of disability legislation and promised to fight any move to target such a group.
Police officers cannot be made redundant, but Acpo is lobbying the Government to change the regulations. Officers on "restricted duties" cost the police service some £40m in salaries.
Peter Fahy, the Chief Constable of Greater Manchester and the Acpo spokesman on workforce development, stressed that it was not the intention to introduce compulsory redundancies, but Acpo wants the ability to seek voluntary redundancies. He said: "In most forces around 10 per cent of officers are not fully fit for duty. Some will have physical issues with injuries sustained on duty, some may be suffering psychological issues and are no longer able to handle conflict on the street. Some are not available for shift work and so their flexibility is reduced and that can breed resentment among other staff.
"In the past forces used to give out medical pensions. But we reined back because it was so expensive. It means that we now have a number of officers working in our forces who are not fully fit. Forces can accommodate a number of them by putting them in jobs that do not require fitness. But as the financial situation bites and spending cuts come we need to look at that again.
"We are aware that lots of officers have given good service, but on the other hand we are aware that in other sectors there would not be the same accommodation."
The plan is to introduce a voluntary redundancy package which can be offered to officers who are on "light" or "restricted" duties. It would, Mr Fahy accepted, need to be more lucrative than the sum officers would get if they were to take the pension entitled to them at that moment in time. But it would be less than the pension the force would be required to contribute to should the officer continue working in a back-office function until he or she had worked the 30 years required to claim a full pension.
"At the moment a pension locks people in and creates an incentive for people to stay because the amount you are entitled to increases, especially in the last five years of your service," Mr Fahy said. "If you have an officer who is injured very early in their service that officer could be in employment for the next 30 years. We have not come up with an easy way to get through this but it is certainly an issue that forces are raising.
"In some ways it is difficult to see how it would work. We would look to put together a redundancy package. But because of the sort of guarantee officers have at the moment it would need to be pretty attractive. Another thing we have discussed is offering them positions as civilians."
Any move to target unfit officers would be particularly contentious, especially in the wake of the Raoul Moat incident in which PC David Rathband was left blind after being shot in the face.
Critics have suggested that the proposal is unfairly targeting officers who have been injured in the line of duty. And some fear it could force injured officers, scared of losing their jobs, back on to the streets before they are ready.
Ian Rennie, the general secretary of the Police Federation, said that if injured officers are to leave forces they should be given full medical pensions.
He said: "The Police Federation believes that the current number of officers on restricted duties is as a result of forces seeking to achieve Home Office police ill-health pension targets over a number of years, together with the poor management of the performance regulations.
"The Police Federation will continue to support any member on restricted duties who is subject to these procedures and will challenge any action taken by forces that is potentially discriminatory on the grounds of an officer's disability."
Deborah Munday, chairwoman of the NDPA, added: "To be injured while doing your job is bad enough and takes a long time to get used to, and you feel very vulnerable. To learn that you could be targeted in this way makes that even worse."
Case study: PC who believes injured officers can still be useful
PC Albert Williams, Humberside Police: One weekend seven years ago PC Albert Williams was chasing a suspect following a fight outside a nightclub when he fell over, fracturing his shoulder in nine places.
In a hospital corridor he sat and cried after being told by a surgeon that he would never be able to raise his arm above waist height and his career as a frontline police officer was effectively over.
He refused to accept his fate and set about proving the surgeons wrong. Following a successful operation to re-wire his joint, PC Williams rejoined the force.
He would eventually resume full duties. But for the next nine months PC Williams, who has worked on firearms teams and riot squads during his 22 years in service, was placed on light duties while his arm healed.
"I did clerical work in the police station," he said. "The task force I was working on at the time was regularly doing drug busts and I would sit in the office and plan them. Rather than taking it in turns to do plans, I made it my responsibility. I was still a part of the team, the only difference being I was not out on the streets with them."
Unsurprisingly given his experience, PC Williams is strongly against offering injured officers redundancy packages.
He added: "Just because an officer is not out on the street does not mean they cannot make a valuable contribution. If an officer is seriously injured then they should be given the opportunity to carry on a worthwhile career within the organisation.
"I know that some people might think we are playing the system but that is not true. I could have given up. I could probably have left with a medical pension. But that is not what we want. What we want is to be police officers, that is why we joined the force."