DENVER (AP) — Saying Southwest Airlines is neglecting workers and its customers, baggage handlers are bringing attention to the company’s slide in on-time performance as they seek a new contract.

Workers are picketing and handing out leaflets to passengers at 16 airports across the country Tuesday, including Denver, Seattle, Los Angeles/Ontario and possibly Kansas City..

For years, Southwest was the most punctual of big U.S. airlines but it stumbled after trying to squeeze in more flights. It has backed off and says it is seeing improvement.

Union president Charles Cerf (SURF) says there’s often only one worker pulling bags out of Southwest’s new larger planes, which he says has contributed to delays. Besides increasing staffing, the union also opposes creating part-time jobs.

Southwest says the number of bags handled by its workers has declined.