Almost 7,000 firefighters' jobs have been cut over the past five years, leading to warnings that the service is being "dismantled".
The Fire Brigades Union (FBU) said there could be a "disastrous" impact on safety because of job losses and station closures.
Research by the union found the number of uniformed fire service personnel in England fell by 6,716 in the last five years - a reduction of 14.5%.
The biggest cuts have been in the North West (22.3%), Yorkshire and the Humber (17.4%), North East (17%), South East (16.6%) and London (13.9%), the study showed.
The figure includes full-time firefighters, retained firefighters and control room staff.
The number of fire stations has fallen by 30, or 2.1%, in the same period, according to the study of official operational statistics.
The FBU said although there has been little change in the number of fire stations in most regions of England over the past five years, there has been a "significant" shift in provision, with many formerly wholetime stations now operating on a retained, or mixed wholetime/retained basis rather than closing.
The biggest single loss in a city has been 10 fire station closures in London.
There has also been a reduction of 101 fire engines, although some fire brigades increased their stock of vehicles.
Some authorities have replaced traditional appliances with smaller firefighting vehicles which maintain response times but with smaller crews, said the union.
The operational life of some appliances has been extended over the past few years.
The FBU is warning of further job losses and cuts next year.
General secretary Matt Wrack said: "Our figures show that the fire and rescue service in England is effectively being dismantled, and the very worrying thing is that it's not going to end here - we know more cuts are on their way.
"The fire and rescue service simply can't take any more cuts. How can this Government possibly expect communities to believe they are being protected from fire and all the other risks posed by extreme weather, terrorist threats and all the other challenges facing us in our society?
"This Government with its ruthless austerity agenda have put fire and rescue services on a trajectory that is frankly heading for a disaster in terms of public and firefighter safety.
"They are making it very clear that they care more about cost savings than they do about the safety of this country's citizens and of the firefighters who risk their own lives to protect them."