Firefighters could go on strike as early as Tuesday, September 7, brigade union leaders have warned.

More than 50,000 union members have started voting on whether to launch a fresh campaign of industrial action, with the result due on Tuesday, August 31.

Once the result of the ballot is in, the Fire Brigades Union has to give employers seven days' notice of a strike, making September 7 the earliest possible date.

Yesterday (August 16) military personnel began training at the Fire Service College in Moreton-in-Marsh, Gloucestershire, in preparation for a strike.

Andy Middleton, the county's FBU brigade chairman, warned last week that firefighters might not respond to emergency incidents from the picket line, as they did during strikes in late 2002 and 2003.

Barry Stockford, the county's FBU brigade secretary, who represents 550 firefighters in Oxfordshire, said: "A strike would not necessarily be called on September 7 but that is the earliest possible date for it to start.

"At the moment, the employers are refusing to come back to the negotiating table and claim it will take six weeks to read a 20-page document. The FBU, together with other unions, has written to the employers, urging them to reopen talks."

The Transport and General Workers' Union and other leading unions have written to Deputy Prime Minister John Prescott urging employers to reopen negotiations, warning that the dispute could "sour industrial relations".

The strike ballot followed the surprise breakdown of talks earlier this month over a 3.5 per cent wage rise, due to be backdated to last November, and a further payment of 4.2 per cent from last month, to bring salaries for qualified staff up from about £21,000 to £25,000.

John Farrow, the county council's executive member for community safety, who has taken part in the pay negotiations, was unavailable for comment.

One sticking point in the dispute is Bank Holiday working, with the employers asking firefighters to carry out normal duties on the eight public holidays, while the FBU says it should be restricted to work similar to night duty, with rest periods.

In Oxfordshire, chief fire officers say they are happy with working arrangements on Bank Holidays.

Firefighters in the county say they will strike reluctantly over pay, not Bank Holiday work patterns.