A series of strike ballots are being held among workers at Luton Airport including firefighters, security guards and baggage handlers in four separate disputes over pay and zero hours contracts.
Members of Unite employed directly by the airport, Menzies Aviation, Clece Care Service Ltd and International Currency Exchange will start voting next week on whether to launch campaigns of industrial action.
The results will be announced in mid-May and any action could start by the end of next month if there is support for walkouts.
Unite officer Ian Maidlow said: "Luton Airport workers, regardless of their employer, deserve a decent rate of pay for their work and to be treated fairly by management.
"These ballots demonstrate that members will no longer accept paltry pay packets and unfair treatment while their bosses constantly squeeze every last penny to boost profits."