Labour has accused the coalition of overseeing a “shocking” 5,000 cut in police dealing with 999 emergencies.
Figures released under freedom of information laws suggest the number of “first responder” officers has dropped by 5,261 since the general election.
David Cameron has repeatedly insisted that frontline police have not been affected by cuts to budgets.
But shadow home secretary Yvette Cooper, who uncovered the latest details, said they showed that his claims were “bogus”.
HM Inspectorate of Constabulary defines “first responders” as those responding to 999 calls, attending traffic accidents and being first at the scenes of crime and other incidents.
The forces that have apparently suffered the biggest culls include Devon and Cornwall, which had lost 540 “first responders” (25% of its total) between March 2010 and last December, and West Midlands, which lost 1,023 (19%).
The total figure is likely to be significantly higher, as only 23 of 43 forces have so far provided data.
Ms Cooper said: “This steep fall in the frontline teams who respond to 999 calls just goes to show how damaging it is for the Government to cut 16,000 police officers.
“We have consistently said the Government needs to change course and that frontline services are being hit by the 20% cut to police funding. The evidence is stacked against the Government and against their bogus claims about protecting frontline policing.
“Whether it is 'visible' or 'frontline' policing, however the Government want to phrase it, Theresa May and David Cameron's decision to cut 16,000 police officers is causing huge damage to police forces, and it is communities who will ultimately pay the price.”