Chancellor Gordon Brown has said that a 16% pay rise for firefighters - without savings from new working practices - would be unaffordable.

His comments, on the third day of the latest strike by firefighters, contrasted with a more conciliatory approach from Deputy Prime Minister John Prescott, who held out the prospect of a 16% rise over three years.

Gordon Brown: Said his 'iron resolve' would remain

The Chancellor said the inflation-busting deal, discussed in pay talks overnight on Friday, would cost Britain more than �500m, and �450m for England alone.

"Sixteen per cent pay rises are simply not affordable," he said, adding that the Treasury would not increase funding to councils to pay for the increase and bring to an end the strike.

But Mr Prescott, appealing to firefighters to end the strike and return to talks, suggested such a rise was possible but may be "better washed over three years rather than two."

Call for calm

Fire Brigades Union leader Andy Gilchrist - who visited a picket line in Luton, where he began his own firefighting career, on Sunday - said the government needed to sort out its "confusing messages" before negotiations could restart.

Andy Gilchrist visited striking firefighters

"We will not be hoodwinked into negotiations when one half of the government is saying one thing, and the other half is saying something else."

TUC general secretary John Monks called for a return to "calm reasoning" and an end to recriminations in the dispute.

But he warned the pay row had ramifications for the relationship between the government and the trade unions in general, saying: "If things fester, then they get worse."

Five people died in house fires on Saturday - and a sixth on Sunday - placing the stretched military cover under the spotlight.

'Reform and productivity'

Speaking on BBC One's On the Record, Mr Prescott did not rule out extra funding leaving the path open for further negotiations over a 16% rise.

If it was just �1m it would be "absolutely stupid" not to find it, he said.

But finding �100m would be different.

And he said a 16% pay rise across the public sector would cost �16bn.

The government is coming under increasing pressure from Britain's biggest trades unions to bring a swift end to the fire dispute.

The public services union, Unison, joined the Transport and General Workers Union and Mr Monks in condemning the approach adopted by ministers.

But ministers have stressed that any pay deal will have to involve comprehensive reform and modernisation.

Appearing on GMTV's Sunday Programme, Mr Brown said any deal would have to be paid for by reform.

"The issue will come back to reform and productivity. There can be no money from reserves. We have made that clear."

Five dead

As informal negotiations continued over the weekend, the armed forces and non-striking part-time firefighters carried on their efforts to maintain emergency cover.

The fire-related death toll during the strike rose to six at 1020 GMT on Sunday when the body of an 80-year-old woman was discovered by neighbours at her house in Penzance, Cornwall.

She died of smoke inhalation after a discarded cigarette set light to furniture.

Elsewhere hoax calls have still been hampering the stand-ins' work, although fire crews have also continued to leave picket lines and help out in several of the most serious incidents.

Gas cylinders

At one, strikers assisted soldiers to search and evacuate a smoke-filled three-storey block of flats in Halifax, West Yorkshire early on Sunday morning.

In Oldham, Greater Manchester, people living near to an MOT centre had to be evacuated as a precaution after it was thought gas cylinders might explode.

Brigadier Roger Brunt, operations director of Operation Fresco, said the military had so far coped well but there was no room for complacency.

"I am confident that the servicemen and women involved in the operation will be able to cope with whatever is asked of them over the eight-day period."