An estimated 35 out of 56 brigades were thought to have joined the action and were only answering 999 calls in protest at a delay in their pay increase.
Yesterday the dispute, which began in Norfolk, had spread to Cheshire, parts of London and East Anglia.
Dave Williams, of the Fire Brigades Union in Cheshire, said: "Most of the fire stations took a decision at 9am to do emergency calls only.
"We haven't coordinated the action, although we understand the justifiable anger, but it quickly spread. We are awaiting the outcome of national talks.
"Hopefully things will be back to normal by the start of bonfire night."
Andy Gilchrist, general secretary of the FBU, and his deputy, Mike Fordham, were meeting employers' leaders for private talks.
The employers insisted that the union had known the deal would have to be ratified by the Audit Commission, which could not be done until the new year.
But the FBU says the 7% should be paid in full tomorrow.
The union's executive will meet today, and could come under pressure to hold a new ballot on the June agreement.
Neil Day, secretary of the Norfolk FBU, said: "What happens next really depends on what Andy Gilchrist returns with out of the negotiations.
"If that is not satisfactory it may well spread across the country. Our members are 100% taking part in this action. We are communicating in various ways - by telephone, fax, email, mobile phone and text message. We were contacted by firefighters from Wrexham, who had seen us on the television. Shortly after, they were taking part in the action."
The FBU said the action would affect routine fire inspections, community advice work and paperwork.
Matt Wrack, London regional organiser for the FBU, said: "London firefighters are extremely angry at the employers' decision to stage the next phase of their pay increase, but are also protesting at the decision to scrap long service pay, introduce cuts in some pay rates, and scrap longstanding FBU policies."
A spokeswoman for the Local Government Association said: "The employers' position on the payment schedule is not going to change. They are only entitled to 7% if they meet the two conditions clearly set out. Neither has been met."
She said that nevertheless, "as a gesture of goodwill", half the amount would be paid.
Tony Blair's official spokesman said: "It's for the two sides to get around the table and work this out.
"Clearly, dialogue is the way to resolve this rather than industrial action which is to no purpose."
The deal and its conditions
· The strikes began over claims that the government will pay only half of 7% of a phased 16% increase, due tomorrow, with the remaining 3.5% paid in the new year.
· Under the 16% agreement, struck in June, 4% was paid immediately, backdated to last November, with 7% due on November 7, followed by a final rise of 4.2% next summer.
· The employers' position is that firefighters were entitled to 7% if two conditions were met, but neither condition (one is on modernisation) has been met.
· The original fire strike was centred on the unions' demand for a 40% pay rise for its members, which would have brought firefighters' annual pay up to £30,000.
