A group of union workers at Sky Harbor Airport protested their wages on Monday.

The gate agents, baggage loaders and other ground employees are in the midst of bargaining on a new contract with their employer, Piedmont. Piedmont is a small airline wholly owned by American Airlines.

Their current contract has a base starting rate between $8 and $9 an hour.

According to Paul Castañeda with the Communication Workers of America, because Arizona’s minimum wage is $10.50, Piedmont pays workers a “city differential” to make up the difference between the base rate and the minimum wage.

“However, all their bonuses and everything are based off their base rate,” Castañeda said. “Which is still $8.05 or $8.50 an hour, in some cases.”

American Airlines employees, on the other hand, start between $13 and $14 an hour, Castañeda said. Monday’s protest was to put pressure on Piedmont and American before another bargaining session is held next week.

Jackie Jennings, a spokeswoman for Piedmont, was not authorized to do an interview but sent this statement:

"Piedmont and union representatives have worked collaboratively to make good progress on a significant number of proposals, and a majority of those proposals have been mutually resolved. We look forward to our next working session next week, and hope to reach a tentative agreement that provides a secure and sustainable future for our team."