Critical talks to end wildcat action by firefighters in Bradford were continuing today as crews steeled themselves for the busiest night of the year.

National union leaders were meeting management in London in an attempt to stave off further industrial action which has broken out across the country.

It threatens to unravel a deal over the long-running pay dispute which led to an all-out strike.

Firefighters around Bradford yesterday joined the unofficial action where only 999 calls are answered.

Unofficial sources said as many as 23 of the country's 56 fire brigades were hit by the action.

Fire Brigades' Union general secretary Andy Gilchrist and his deputy Mike Fordham were today meeting John Ransford, one of the employers' chief negotiators, and other management officials in a bid to settle the row.

The dispute flared after it emerged that the second stage of a 16 per cent wage rise will be paid in two parts - 3.5 per cent on Friday and another 3.5 per cent in the New Year after it is approved by the Audit Commission.

Local authority leaders insisted the FBU knew external verification was needed before the 7 per cent could be paid in full.

But Sub-officer Alan Holdsworth, an FBU union member at Stanningley which covers large parts of Bradford includng Bradford Moor and Thornbury, said: "We feel very let down. We only ever take action as a last resort.

"We were promised seven per cent and it appears they have gone back on their word.

"Morale is very low. We accepted 16 per cent - but reluctantly to end the dispute.

"We were advised to accept because we would not get a better deal."

Steve Cawood, FBU branch secretary at Idle fire station, said the union would never condone the unofficial action.

But he added: "We have done everything we were asked to do as part of the agreement. The employers are saying they have done everything right.

"By doing this they have upset a lot of people. Everybody is angry."

Councillor Tony Niland (Lab, Bowling), chairman of West Yorkshire Fire Authority's Personnel and Training Committee, condemned the unofficial action saying negotiations had to be the way forward.

"I am deeply concerned that they have taken this form of action.

"Let us hope we do not go through this silly period again."

The FBU executive is due to meet tomorrow to decide its next move.

One member of the executive said yesterday that the pay deal could now be ripped up, sending the dispute back to square one.

He refused to rule out the possibility of a ballot for fresh industrial action.

Mr Ransford said he was "surprised and confused" at the new dispute and warned that it would make some employers nervous about paying the first instalment of the pay rise on Friday.

"A lot of firefighters have misunderstood what the position is," he said. "It is absolutely clear that the seven per cent cannot be paid until verification from the Audit Commission, which is expected to happen in the New Year.

"The rise will be backdated to November 7. If they don't sign up to this stage of the proceedings they will get nothing.

"If there is disruptive industrial action, the employers will feel that the firefighters are not honouring their part of the bargain and the deal which was put together could start to unravel."

The Chief Fire Officers' Association urged firefighters to return to normal working and insisted the union knew the deal was going to be paid in stages.

President Jeff Ord said the illegal action was not the way to resolve the dispute although he understood that firefighters were feeling "angry and confused".

Firefighters came under attack from gangs of teenagers launching fireworks and hurling bricks and eggs in Bradford last night.

Crews at Bradford and Stanningley stations were targeted as they tackled five separate incidents in Bradford Moor.