BAA workers have voted in favour of strike action that could close Heathrow and five other UK airports.
The ballot came after the Unite union rejected a one per cent pay offer from the airport operator.
Airports will have to close on any strike days, as essential staff including firefighters are due to take part in the walkouts.
BAA also runs Southampton, Edinburgh, Stansted, Glasgow and Aberdeen airports.
The airports operator said: "We regret the uncertainty this vote has already caused our passengers and airline customers.
"Fewer than half of those people eligible to vote have done so and we do not believe this result provides a clear mandate for strike action."
The union said 74.1% of the 3,054 staff who voted said yes to strike action.