Plans to merge county-based fire service control rooms have caused anger amongst brigade staff in the south.
Each brigade currently has its own control centre
The government is looking at a proposed merger of the call centres into wider, "more efficient" regional units.
That would see control rooms in Buckinghamshire, Oxfordshire, Berkshire, Surrey, Hampshire, the Isle of Wight, West and East Sussex and Kent merged to form a single centre for the south east.
Meanwhile, Dorset, Wiltshire, Gloucestershire, Avon, Somerset, Devon and Cornwall would be formed into a centre for the south west.
The Fire and Rescue Service Bill - published on Tuesday - would give the government powers to undertake a regional overhaul of how the brigades run.
Fire Brigades Union (FBU) bosses are concerned that such a move could ultimately lead to a national control room taking all calls.
Roy Goring, FBU spokesman, said: "The fire services seem to work really well in the size they are.
"And, who knows, after a national control centre who says it does not go to a call centre in India?"
There are also fears that the move to regional centres would lead to job losses and a lack of vital local knowledge.
One control centre operator, Sharon Eames, told the BBC: "If people are trapped inside burning buildings, you have to try and gain the best information you can under very difficult circumstances.
"Sometimes it can help the caller if they know you have an idea of where they are calling from."
But a spokesman for the Office of the Deputy Prime Minister denied that local knowledge was essential.
A spokesman told BBC News Online: "The reasons behind this are that it will give greater resilience for the brigades when they are dealing with large-scale emergencies, which are much better handled at a regional level.
"Local knowledge plays a very, very minor role in the control rooms anyway."
He added that in London, where a regional control centre was already operating, dealing with each call cost the service just £18.
"If you take the Isle of Wight control room, which I doubt is very busy, it is about £168 for every call that is received," he said.