Unionized workers at Los Angeles International Airport plan a march on Thanksgiving eve to protest what they allege are a contractor's unfair labor practices, it was announced Friday.

Workers with the Service Employees International Union will march on Century Boulevard for about three hours Wednesday afternoon -- among the busiest travel days of the year -- to bring attention to its dispute with LAX contractor Aviation Safeguards, according to Martin Terrones of SEIU United Service Workers West.

Los Angeles World Airports, the agency that operates LAX, did not immediately comment on the plans or potential impacts on airport operations.

According to the union, about 400 airport workers were left without a contract earlier this year when Aviation Safeguards, a division of Command Security Corp. of Parsippany, N.J., terminated union contracts and withdrew all health insurance.

"By allowing the situation to continue, LAX is punishing the good contractors who play by the rules," USWW President Mike Garcia said. "Things at the airport have gotten out of control, and workers are ready to take action."

SEIU represents janitors, wheelchair attendants, skycaps, security guards and other service workers at LAX.