The busy school summer holidays periods at Gatwick airport are forecast to result in 'inevitable' disruption from later this month.
The Unite Union said the strikes will result in'severe delays, disruption and cancellations' over two consecutive long weekends.
Unite is forecasting two key Sundays at the summer peak for the UK's second-busiest airport. The first walk-out is from 28 July to 1 August, with the second week a week later: Friday 4 August until 8 August.
The union is seeking compensation from the airlines affected, including British Airways, easyJet, Ryanair, Tui and Wizz Air.
The workers are employed by four ground handlers, ASC, Menzies Aviation, GGS, and DHL Services Ltd. Aircraft handlers run checks in, baggage handling and aircraft dispatch.
Unite said it has been in negotiations with the four companies since January, but they have failed to make sufficient offers.
Sharon Graham, the union's general secretary, said: 'It's operations but this dispute is entirely of the companies' own making.
With the strike affecting Gatwick airport, a average of 441 daily departures is predicted, with easyJet the biggest airline, followed by British Airways, Tui, Vueling and Ryanair.
Cirium, an aircraft analytics company, said there are expected to be 840,000 seats on those aircraft during the strike.
We are in touch with our ground handling partners and are doing everything within our control to limit disruptions for passengers, a spokeswoman for easyJet said.
The Independent has asked the ground handlers and the airlines for answers.
The world's busiest single-runway airport is Gatwick. This week, the main airline at Sussex Airport said it was cancelling 1,700 flights over the summer peak because of chronic air-traffic control delays.