The walkouts – which, according to data analytics firm Cirium, could impact 6,253 departures – involve security officers at Terminal Five, which is used exclusively by British Airways, and campus security guards, who are responsible for checking cargo that enters the airport.
"The strike action will undoubtedly result in severe delays and disruption to passengers across the airport but this dispute is a direct result of Heathrow Airport’s stubborn refusal to pay its workers fairly," said Unite regional coordinating officer Wayne King.
However, Heathrow said it will not let "unnecessary strikes" impact the holidays of its passengers.
