Airport operator BAA will find out today whether thousands of its workers will strike in a dispute over pay that could cause disruption to flights at the end of the summer holidays.
The Unite union asked more than 6,000 of its members who work as firefighters, engineers and support and security staff at Heathrow, Stansted, Southampton, Glasgow, Aberdeen and Edinburgh to vote for industrial action over what it calls a "measly" pay offer.
Unite said that BAA staff already accepted a pay freeze in 2009 and that this year, the company had offered staff a 1% pay increase, plus 0.5% which was conditional on changes to a sickness agreement.
Unite also wants workers to receive a performance-related bonus that was promised to them if the company hit a certain financial target.
BAA said it made a "reasonable" offer at a time when "BAA and its airline customers are seeing a decline in passengers due to the impacts of recession and volcanic ash".
The result of the ballot, which closed today, is expected to be revealed later.