350 Unite members employed by Menzies will take part in strike action from 4am on Friday December 16 for 72 hours.
The three day strike action will affect flights operated by 10 major airlines from Heathrow Terminals 2, 3 and 4.
The dispute centres around a pay offer made to cargo workers but which has not been extended to baggage handlers.
Cargo workers were offered a 9.5% pay increase backdated to May 2022 and a further 1% from January 2023, the union said.
Unite general secretary Sharon Graham said: “Menzies needs to have a long hard look at itself. This is a highly lucrative company, which has made a fair pay offer to one group of its workers but isn’t prepared to make a similar offer to its ground handlers.
“Unite is entirely dedicated to defending its members’ jobs, pay and conditions. Our members at Menzies will continue to receive the union’s complete support.”
Miguel Gomez Sjunnesson, executive vice president Europe at Menzies Aviation said: "We are well prepared for further industrial action and are working closely with key partners to put in place robust contingency plans.
"We remain committed to seeking a resolution on the pay talks in our ground handling operations so our employees can receive their increase now, and hope to be able to reach an agreement which is workable for both the business and our employees during our meeting with unions on Tuesday."
Airlines that are likely to be affected by the three-day strike are Air Canada, American Airlines, Lufthansa, Swiss Air, Air Portugal, Austrian Airlines, Qantas, Egypt Air, Aer Lingus and Finnair.
A Heathrow spokesperson said the airport was "aware of industrial action proposed by Menzies colleagues". It said it "encouraged airport partners who would be affected to continue with their contingency planning and we will support them to minimise the impact on passengers, should the strike go ahead."