Policing has been left at a tipping point by government cuts and is on the verge of failing the public and struggling to detect crime, a senior police chief has said.

Dave Thompson, the chief constable of the West Midlands force, said agreement was needed on what the police should stop doing. It is an idea discussed privately by police chiefs and carried out by stealth by some forces.

“The public’s experience is policing that is less visible, less responsive and less proactive,” he wrote in a post on the National Police Chiefs’ Council (NPCC) blog.

“Core aspects of policing – such as answering calls, attending emergencies, investigating crime, bringing offenders to justice and neighbourhood policing – are being pushed beyond sustainability, and are in danger of becoming ineffective, to the detriment of confidence in the police.”

Thompson, who leads on finance and resources for the NPCC, took aim at the Conservatives’ approach to policing since they came to power in 2010.

“The government has had a partial view of policing in the last few years,” he wrote. It was very interested in terrorism and high-end threats but less focused on local crimes, which had been left for forces and police and crime commissioners to manage amid steep budget cuts.

“This more local agenda has many positives in setting priorities but it has come with steep budget reductions and a widening mission,” he said. “There has been a real-term reduction of police budgets of 19% since 2010, but ranging between 11- 25% across forces.”

Thompson said police had improved in the fight against terrorism and serious and organised crime. “But the gains we’ve made have come at a cost to perhaps the most important parts of policing for the public.

“Crime is rising and so is the demand on our service. The calls do not get answered as quickly as they did. Officers are not as fast at responding to emergencies and more crimes are dealt with on the phone. Fewer high-volume crimes like thefts are investigated and as a result fewer offenders brought to justice. The visibility and proactivity of neighbourhood policing is much reduced.”

He added: “Bluntly, our ability to manage the big threats and protect the vulnerable, yet still be the traditional police the public want and need, is becoming ever harder. We are in danger of pursuing efficiency to the point of ineffectiveness – where we can process the work but we’re not detecting crime as we should be and not meeting public expectations.”

Thompson said all this was putting a strain on officers. “Letting victims down or sharing their sense of dissatisfaction in the service they’ve received chips away at morale.”

He cited a National Audit Office report last month that castigated the government’s handling of the police. “The NAO assesses the government did not fully understand the actual impact of these cuts on police forces. Policing is at the tipping point – and we need to move on from here.”

Thompson said police, Home Office ministers and officials were preparing a joint bid for more money from the Treasury, and he said police may need need to retreat from some services provided at present.

“I hope we will see more money for policing as we make an evidence-based case for investment,” he wrote. “However, it is equally important that this process results in a clear collective agreement on what policing should do in 2019 and the years beyond. Part of that equation may be jointly considering what we should not or cannot afford to do – because the public deserves to know.”

A Home Office spokesman said: “We remain committed to working closely with police and delivered a £460m increase in overall police funding in 2018/19, including increased funding for local policing through council tax.

“We are also working with the police to put forward the evidence to ensure they receive the resources they need to do their vital work at the next spending review.”