General secretary of the Fire Brigades Union Matt Wrack said the independent review into the services was "just a fig leaf for slashing our fire and rescue service to bits".
David Cameron has promised to protect frontline services. That has been exposed as a lie over the past three years as the fire service has faced the biggest cuts in its history.
It is not just the Fire Brigades Union warning about this. Increasingly others in the fire service, including chief officers, are concerned over our ability to deliver this essential service.
Fire stations are being closed and fire engines are being axed. Last year alone a further 1,200 firefighter jobs were cut.
All these cuts mean a poorer service for the public. They mean waiting longer for a fire engine if you have a fire or other emergency. Ken Knight is attempting to bury all these facts in order to justify further cuts in the Government's forthcoming spending review.
Sir Ken Knight, former chief Fire and Rescue adviser for England who carried out an independent report on the services, said "much more can be done" to improve efficiency.
He said: "As a firefighter for over 40 years I know the Fire and Rescue Service in and out. I know firefighters care deeply about public safety and do the best possible job.
"I've seen their capacity to adapt, even in the most trying of circumstances, but my report highlights that there is much more that can be done by the service leaders to make the service as effective and efficient as possible.
"My starting point was to maintain the quality of the service and to protect the safety of the public and firefighters. As I carried out this review I spoke with many services and found that there is widespread variation in the running costs and management decisions.
This presents a real opportunity to get to grips with what is happening and to save public money. Government and the 46 fire and rescue authorities should use it to decide how to transform the service to reflect the modern and safer world we live in today."
England's fire and rescue services could save £200 million a year if they were more efficient, according to a report.
There has been a 40% reduction in call outs and incidents in the last decade and accidental deaths from fires in homes have reached an all time low, yet expenditure and fire-fighter numbers have remained broadly the same.
Services continue to spend according to the budget they are given rather than the risks they have to manage, the independent report by Sir Ken Knight, former chief Fire and Rescue adviser for England, suggested.
There are significant variations between how the 46 different fire authorities operate, with the cost per head of providing a service almost double in some areas to that of others, the report said.