Robin Wilson leads chanting as airport workers and supporters from around the world rally for better wages in Ronald Reagan Washington National Airport last month.. Workers in DC are the latest to join a national campaign for better wages for contracting workers at airports across the world. (Jabin Botsford/The Washington Post)

This post has been updated.

Airport workers at seven of the busiest U.S. airports are going on strike Wednesday night to protest what they say are poor working conditions and retaliation for unionizing.

More than 2,000 workers, including cleaners, wheelchair attendants, and baggage handlers plan to strike at Fort Lauderdale, Philadelphia, Boston, Chicago O’Hare, Newark Liberty and New York’s Kennedy and LaGuardia airports, the Service Employees International Union said.

It’s unclear how the action might impact operations. We’re checking with airports and will update this post as soon as we hear back.

The walkout is part of a growing national campaign for a $15-an-hour minimum wage for the lowest-paid airport workers who keep terminals and plane cabins clean, move bags and transport people with disabilities. They work for contractors that serve all major airlines, and some of them are making hourly salaries as low as $6.75, union leaders say.

“Despite working fulltime, they cannot afford to rent a room for themselves let alone take care of their families,” said Marc Goumbri, an SEIU spokesman with the workers campaign. “The workers have a right to get together under federal law and fight for better working conditions, but when they do so they face retaliation from the contractors.”   

[Washington-area airport workers join fight for $15-an-hour minimum wage]

It is unclear how the strike, expected to start around 7:30 p.m. and extend until Thursday, will impact airport operations. It comes, however, just days before one of the busiest air travel weeks.  As many as 3.6 million Americans are expected to travel for the Thanksgiving holiday, according to AAA estimates.

Greg Meyer, an spokesman for Fort Lauderdale-Hollywood International Airport, said any actions Wednesday night are not likely to significantly impact service, noting that business is slow at night.

“This is not going to shut down the airport,” he said. “This is not going to cause the airlines to stop flying.”

When workers have gone on strike in the past it has impacted services such as wheelchair assistance and those handling bags at the curb. But he said, “the airlines bring in additional employees and they take over those responsibilities. You still have folks that are disabled that need assistance getting from the curb to the gate so the service has to be provided.”

Solidarity actions are also planned for Thursday in Los Angeles, Minneapolis and Portland, Ore. In Washington, airport workers will join several members of Congress at a morning news conference in support of the $15 hourly wage.

Once contracted directly with airlines or airports, most of these service jobs are now outsourced to companies that compete for the contracts.  Some studies suggest that the growing trend has led to poorer working conditions and lower wages.

Airport workers across the U.S. have held protests, marches and rallies over the past three years, calling for better pay and benefits. Some workers say the low wages force them to work two or three jobs to sustain their families.