Britain's busiest airports could be forced to close unless pay for firefighters and security guards is improved, their union has warned.

The prospect of chaos for passengers was raised when 2,500 members of the Transport and General Workers Union (T&G) voted 2-1 in favour of strikes.

It said Thursday's ballot reflected workers' "sheer frustration" at the pay offer put forward by their employers, the British Airports Authority (BAA).

BAA said the deal amounts to 6.3% over two years and is fair given the present economic difficulties facing the aviation industry.

'Increased workloads'

Union stewards will meet next Monday to plan the industrial action.

We would not do anything to compromise airport or passenger safety

BAA

Tim Lyle, T&G's national secretary for aviation, said: "The vote in favour of strike action represents the sheer frustration at the company's offer, given the increased workloads and responsibilities placed upon BAA employees following 11 September.

"Coupled with the knowledge that traffic figures have improved and the company is in profit, our members justifiably feel that the pay offer falls short of what they deserve."

The T&G said the rejected offer was worth 1.7% from last April, plus �150, then a further �150 from next January followed by an increase of the rate of inflation plus 1% from April 2003.

The workers involved are employed at Heathrow, Gatwick, Stansted, Southampton, Aberdeen, Glasgow and Edinburgh.

Passenger safety

A BAA spokesman said it had good relations with the unions and its workforce and would be holding further negotiations to try and reach a deal.

Low pay, lack of career paths and inadequate training for security workers puts passengers and airport workers at risk

John McDonnell MP

It said the prospect of airports being forced to close remained distant, as no strike had yet been called and the T&G represented only a quarter of its workforce.

But the spokesman added: "We would not do anything to compromise airport or passenger safety.

"We would certainly need to have enough firefighters on duty at any one time to operate normally."

'Inadequate training'

Conservative Party leader Iain Duncan Smith urged the workers not to strike.

He said: "I think people who are charged with the safety of the public in their daily lives, should not strike."

But John McDonnell, Labour MP for Hayes & Harlington, whose constituency includes Heathrow Airport, said he backed the proposed action.

He said: "Low pay, lack of career paths and inadequate training for security workers puts passengers and airport workers at risk."

The threat of strikes is not linked to the nationwide action planned by firefighters next week.

Airport firefighters are already paid more than regular firefighters and are not expected to take part in strike action called by the national Fire Brigades Union.