The threat of damaging late-summer strike chaos at Gatwick remains after a possible solution to the British Airways' (BA) dispute was rejected.

BA management offered the three unions involved a chance to take the pay dispute involving baggage handlers and check-in staff to arbitration.

But the Transport and General Workers' Union (T&G), the biggest of the three, said it wanted a negotiated settlement "rather than having one imposed".

Members of the GMB union have already been asked to support a campaign of industrial action, while more than 8,000 T&G workers will today begin to vote on strike action.

Those voting include 4,500 baggage handlers at Gatwick, Heathrow, Birmingham, Manchester and Edinburgh and 3,700 check-in workers at the same airports and Glasgow.

The third union involved is Amicus.

Outlining the arbitration plan, BA's director of customer services and operations Mike Street said: "Arbitration will allow our customers to book in confidence with the knowledge their summer travel plans will not be disrupted.

"We hope the unions will support our initiative as a genuine opportunity to resolve our differences without the need for disruption for our customers, our employees and our company."

But T&G national officer Brendan Gold said: "We want a negotiated settlement so our members can get the pay rise they deserve and have waited for since January 1 this year.

"That means the company has to move its position. They have told us it will cost just more than £23 million a year to resolve, which is a small sum set against the £869 million our people, who earn between £12,000 and £14,000 a year, have saved each and every year for the company.

"The way to settle this dispute is for the company to move so both parties can agree a settlement rather than have one imposed."

The T&G decided to ballot its BA staff in the pay dispute after initial talks at the conciliation service Acas failed to make enough progress last week.

The unions have rejected a three-year pay offer worth 8.5 per cent or 10.5 per cent if it does not count towards pensions.