Latest survey on impact of spending cuts warns that three forces may not be able to provide effective service in future

Police forces are planning to reduce the number of frontline officers by 5,800 within the next three years, according to the latest official survey on the impact of Home Office spending cuts.

Her Majesty's Inspectorate of Constabulary (HMIC) warns that there is a risk that three forces, the Met, Devon and Cornwall, and Lincolnshire, may not be able to provide an adequately efficient or effective service to the public in future.

The report says 17,600 police jobs have gone since March 2010 to find savings of £749m. This is more than half the 32,400 uniformed officers and civilian staff jobs they now plan to shed by 2015.

The number of expected police job losses is higher than previous official surveys and does not include Britain's largest force, the Metropolitan police, or Cheshire, which have yet to publish their plans for the next three years.

The HMIC report reveals that forces in England and Wales plan to close public access to a fifth of all police stations – 264 front counters are to shut – but are planning to open 137 "public access points" in shared locations such as supermarkets and libraries.

The police inspectorate says the nature of frontline policing is changing, with forces merging response and neighbourhood teams, spending more on police investigations and police protection, and increasing the use of volunteer special constables by 9,000.

But the report adds that despite the fact that many forces have changed the way policing is delivered locally, crime has continued to fall and the response to antisocial behaviour has improved: "A survey conducted alongside this review suggests that on the whole the public have not noticed a change to the service they receive," it notes.

The report, Policing in Austerity: One Year On, says the number of officers that are "visible and available to the public" has fallen by 5,500, including a fall of 5,200 response officers. This has been matched by a rise of neighbourhood officers by 2,300.

But by 2015, forces say they plan to lose a total of 5,800 frontline police officers – a 6% reduction. So far, 2,700 frontline policing jobs have disappeared since May 2010 as a result of the five-year cuts programme.

Sir Denis O'Connor, the chief inspector, said there were particular concerns about the Met. Britain's biggest police force needed to produce a plan by this autumn detailing how it would tackle a £233m gap in its funding on top of savings of £500m that have already been identified, he said.

"There has been a pause because of all the changes at the top of the Met, executive and politically, and the Olympics," he said. "That combination has paused things. So they've got £233m to find. They make up the bulk of the outstanding money to be found nationally.

"The second thing is they have some performance issues. Crime has been bubbling up and down for them and their satisfaction levels are low. So they've got limited timescales and a lot to do."

The chief inspector added that it was important to give the Met space to detail their plans: "We would all rather this was done well, rather than done badly."

He denied the Met was "on a cliff-edge" as claimed by some insiders, and the force itself has denied speculation that as many as 8,000 police jobs could go in the capital.

O'Connor said the problems facing Devon and Cornwall and Lincolnshire were of a lower order.

Police cuts Photograph: Graphic

Forces have to make savings of £2.4bn by 2015 as a result of a 20% cut in Home Office grants to police authorities. The HMIC says the planned reduction in the total number of police jobs, including non-frontline civilian staff, has reached 32,400 by 2015, including 15,000 uniformed officers, of whom at least 7,600 will not be in frontline roles. The bulk of the cuts will fall on the non-frontline roles in policing, whose ranks are facing a 33% reduction by 2015.

The inspectors say, however, that these "incremental cuts" are not sufficient to transform police efficiency if they are to avoid essential back office functions simply being transferred to frontline staff. Forces need to do more to find savings through collaborations and in partnerships with the private sector.

The report warns strongly that police must start to prepare for even deeper cuts in the next Treasury spending round for the period beyond 2015.

O'Connor said forces had risen to the financial challenge by cutting their spending while largely maintaining the service they provide the public, but they still need to transform the way they work to prepare for the next round of spending cuts.

Paul McKeever, of the Police Federation, said: "The serious disorder last summer highlighted in the Guardian/LSE research published today demonstrates that police officer numbers really do matter. Whichever way you cut it, the resilience of the police service to be able to react to whatever is thrown at it is being threatened."

The policing minister, Nick Herbert, said: "This report makes it clear that the frontline of policing is being protected overall and that the service to the public has largely been maintained. The proportion of officers on the frontline is increasing, the number of neighbourhood officers has gone up, crime is down, victim satisfaction is improving and the response to emergency calls is being maintained.

"While there are particular challenges in three forces, we know that the vast majority are rising to the challenge of reducing budgets while protecting service to the public."

The shadow home secretary, Yvette Cooper, accused ministers of risking public safety. "The HMIC report shows the proportion on the frontline will be falling as a result of the scale of the cuts, because so many officers are coming from the 999 units," she said. "And that's why I think this is really serious, because the government should be cutting crime, not cutting the police."