Neighbourhood policing – pioneered in Devon and Cornwall but now at critical levels – must be protected, the Police Federation said.
Officers spoke out as the Independent Police Commission warned forces were in danger of "beating a retreat from the beat" to a "discredited" reactive form of policing.
Former Met commissioner Lord Stevens, who chaired the commission, said: "Our commission has looked at how we can change policing to keep a community-based approach, stopping what we see as the risk of beating a retreat from the beat."
He added: "Neighbourhood policing is the golden thread that runs through it all, and is foremost in my mind to secure a service fit for the 21st century."
The concept of community policing was pioneered by John Alderson, the former Chief Constable of Devon and Cornwall Police, in the late 1970s and early 1980s. It has since become regarded as the heart of modern policing.
But Sergeant Nigel Rabbitts, chairman of the Police Federation in Devon and Cornwall, said because neighbourhood policing delivered results which couldn't be easily measured, it was "very vulnerable" to cuts.
"One of our concerns is that neighbourhood policing is supported across the country but is not supported within Government funding for policing," he said.
"It is the first area that's looked at for cuts and for alternatives of providing a fully warranted officer to fulfil that role.
"We had the diversion into community support officers, and in some cases volunteers, because it seems to be identified as an area where savings can be made.
"In reality, it should be a priority area because it is the bedrock of the office of constable and how communities engage with the police."
In a letter to MPs this summer, Police and Crime Commissioner Tony Hogg and Chief Constable Shaun Sawyer warned "the number of officers available for neighbourhood policing – the bedrock of policing intelligence and community safety and engagement – is already at a critical level across Devon, Cornwall and the Isles of Scilly".
Without, this year's 2% increase in the force's share of council tax bills, the neighbourhood teams would have fallen to just 125 officers to cover communities spread over 4,000 square miles.
Mr Hogg said: "Last year I took the decision to protect a visible police presence in all our communities by reversing the decision of the old police authority to cut officer numbers to 2,810. By increasing the council tax precept officer numbers remain above 3,000 and, while we are committed to doing the same again in the next few years, we are also aware of further public sector threats to policing budgets in the years ahead.
"The people of Devon, Cornwall and the Isles of Scilly, and the police officers who keep them safe, can be sure of my determination to maintain the number of police officers but, to support them and reduce demands on them, I also want to find ways to mitigate the impact of reducing budgets on our communities.
"It is absolutely vital that we look at new ways of working and that the police force changes its culture to make better use of those prepared to volunteer from our communities. Perhaps the most obvious way this can happen is for the force to recruit more special constables. I have tasked the chief constable to increase the number of specials from 600 to 800 in the coming years.
"But there is more that can be done. That doesn't mean I want to see members of the public chasing criminals but if we can harness the energy of those who want to help improve their communities, it will free up police officers to do just that."
Yesterday's report, which was commissioned by Labour, set out 37 recommendations to transform policing in England and Wales, with a focus on getting officers back on the beat in communities.
At it's launch, Labour leader Ed Miliband said: "These are tough times and it is more important than ever that we get maximum value for money from every penny of taxpayers' money that is spent on the key public services.
"We recognise that after the next election, a One Nation Labour government will be seeking to improver public services in tough fiscal circumstances.
"That is why the commission is absolutely right to focus on the importance of savings and efficiencies. Crude salami-slicing without reform, as pursued by this Government, simply stores up costs later down the line."
One of the commission's recommendations is that the social purpose of the police should be enshrined in law, bringing "much-needed consensus" to what the public expect of the police.
Policing Minister Damian Green responded: "Recorded crime has fallen by more than 10% since the Government came to power and we have put in place long-term reforms to help the police continue that downward trend.
"We have stripped away targets and red tape to free police from desk-bound jobs; we have installed the National Crime Agency to take on organised crime; we have installed a College of Policing to professionalise policing; we have modernised outmoded pay and conditions; and we have introduced a newly-reinforced ethical framework to ensure police conduct is on an equal footing to cutting crime."