The state of policing in England and Wales is "in intensive care", with experienced officers leaving in droves, representatives are warning.
Officers who risk their lives and face danger on a daily basis are often "unfairly punished" for their actions, with firearms officers and police involved in pursuits particularly in fear of being "dragged through the courts" simply for doing their jobs, the chairman of the Police Federation will say at its annual conference.
The need for better protection and support for officers who volunteer to carry firearms and for those engaged in police response and pursuit driving are expected to be the focus of the two-day meeting in Birmingham, which starts on Tuesday.
"If change isn't imminent, the public can expect both a less experienced workforce, as officers reach the end of their tether and choose to leave, and one that can no longer do all that is asked of it," chairman Steve White will say.
"Too often those running towards danger are unfairly punished for their efforts, whether physically or disciplinary.
"Officers assaulted, but offenders facing no extra punishment. Firearms officers who pull the trigger being treated as guilty from the outset.
"Those involved in pursuits being dragged through the courts despite the specialist driving training they receive."
Under the theme Protecting the Protectors, the conference will explore the need for a change in approach, funding and legislation to protect those charged with protecting the public.
Last year Mark Williams, chairman of the Police Firearms Officers Association, warned that forces are struggling to recruit armed police due to concerns they will end up being investigated for using their weapons.
Despite this, Britain's armed policing strength is expected to grow to more than 10,000 next year as forces beef up their defences against terrorist attacks.
The National Police Chiefs' Council (NPCC) announced last month that since last year the number of firearms officers in England and Wales has increased by 640, with plans to recruit around 1,500 extra officers in total by the end of next year.
The Police Federation, which represents 120,000 rank and file officers in England and Wales, said that workforce figures released in January show that more than 2,700 officers left the service in the 12 month period ending September 2016 - the largest drop for the past three years.
This along with a continuing increase in recorded crime means, "we're not close to breaking point, we're at breaking point," Mr White will say on Tuesday.
"The tide has turned and we're behind the wave, through little fault of our own," he will add.
"Every day officers work tirelessly to stem the flow, but as the 'go to' service for those in need, at a time when partner agencies are struggling to provide the specialist services required, it's the police plugging the gaps.
"We are a police service envied the world over. Without question, the government of the day must invest to keep it that way."
The federation said since 2009 the police service has lost 21,500 officers, with the total workforce including police staff and PCSOs down from 204,500 to 198,000.
Home Secretary Amber Rudd will attend the conference along with Policing Minister Brandon Lewis and representatives from other political parties.