Cardiff Airport security staff who are unhappy with their pay have written to its chief executive and the economy secretary calling for a raise, BBC Wales understands.
Wage campaigners said some staff in the coffee shop were paid more than those responsible for screening passengers.
Workers claim they should be paid more given their responsibilities.
The airport said it was "working towards honouring" the so-called "real living wage".
On Monday, First Minister Carwyn Jones will announce the new "real living wage" rate for Wales - £8.75.
Community support group Citizens Cymru Wales is calling on the airport - which is Welsh Government-owned but run at arms length - to pay the "real living wage", the amount deemed necessary to afford a basic standard of living.
Employers do not have to pay the rate, which is more than the statutory national living wage of £7.50 for those aged over 25.
Cardiff Airport said it does pay all employees more than the statutory national living wage.
One former airport worker, who left the airport because of pay, said: "The pay is just too low now the cost of everything has gone up, wages haven't kept pace.
"I used to be able to support my family ok on my wages, but now we are in debt and one step away from the food bank."
Another, who did not want to be identified, said: "It seems wrong for taxpayers' money to be used to create jobs that don't pay us enough to live on."
Letters will be sent on Monday to chief executive Debra Barber and Economy Secretary Ken Skates calling for action on pay.
The Welsh Government pays the "real living wage" and encourages other employers to pay it.
Last year it said paying the rate made good "business sense".
However, small and medium-sized businesses have said they would struggle if they had to pay it.
A spokesman for Cardiff Airport said: "Cardiff International Airport Limited employees are all paid at rates that are above the National Living Wage and we are committed to working towards honouring the real living wage.
"Cardiff Airport is on a continuing journey of growth and improvement to deliver a sustainable national airport for Wales."