Almost 70 fire stations in England are at risk of closure and scores more throughout the UK face severe downgrading if the Government presses ahead with "unprecedented" spending cuts, union leaders have warned.
The Fire Brigades Union claimed that the service was being downgraded "behind the scenes" without proper public debate.
The worst-hit brigades are in big cities, with 17 fire stations under threat in London, 11 in both West Yorkshire and South Yorkshire and 10 in both Greater Manchester and Merseyside, claimed the union.
Station closures are also threatened in Berkshire, Kent and Dorset, said the FBU.
Officials also reported that scores more fire stations are faced with downgrading, with fewer appliances and firefighters.
Matt Wrack, FBU general secretary said: "People need to realise that this government is now putting public safety at risk. People rely on having a fire station near where they live, so that in the event of any emergency, professionally trained and well-equipped firefighters will come to their aid.
"The cuts have now gone so far that dozens of fire stations are threatened with closure, an unprecedented development in the recent history of our fire service. We cannot just stand back and watch this essential service be systematically dismembered by savage spending cuts.
"People need to understand that behind those big red doors, things are changing in their local fire station. Even where the lights remain on, there could be fewer firefighters, fewer appliances and less fire cover than the public expect.
"Firefighters have excelled again in recent weeks, dealing with floods as well as fires and all manner of emergencies. That's what people expect from their fire and rescue service and firefighters are very proud to deliver an exceptional level of service. But this government is cutting the service to the point where they are putting lives at risk."
The union said it feared fresh public sector spending cuts in Wednesday's Autumn Statement.
A Government spokesman said: "Fire and rescue authorities deliver an incredibly important service for local communities. Every bit of the public sector needs to play its part to cut the deficit.
"However, despite that, fire and rescue, as a front-line emergency service, has been protected with reductions back-loaded to give more time for sensible savings - like better procurement, joint working and tackling outdated working practices - to be made without impacting on the quality or breadth of services offered to communities."