Some 23,500 police support staff have been cut under the Tories on top of 21,700 officers.
News of the shock figures come amid promises from Prime Minister Boris Johnson to boost the service.
Labour say the “brutal” reductions are a big part of the reason why only 7% of crimes are now prosecuted.
The GMB union, which uncovered the data, warns the cuts to support staff mean forces are squeezed to “breaking point” putting “lives at risk”.
Essential behind-the-scenes services are carried out by the likes of custody officers, call-handlers, police community support officers and scene of crime investigators.
Louise Haigh, Shadow Policing Minister, said: “Police staff have been degraded under the Tories just as much as officers — and we are all paying the price.
“Boris Johnson might talk a good game on law and order, but if he means it, he will reverse these cuts.”
London is the most affected region with 47% or 9,000 jobs going, including 72% of PCSOs.
Overall, 7,000-plus PCSO posts have gone. The Tories made police funding a key manifesto pledge. But the promises only mean they are replacing 20,000 of the officers lost since 2010.
Rachel Harrison, from the GMB union, said: “These cuts are an absolute disgrace.”
The Home Office said: “The Government is putting 20,000 extra officers on the streets over three years. We have considered additional elements, including staff.”