A group of 500 baggage handlers, wheelchair attendants, cabin cleaners, and skycaps at Logan Airport plans to go on strike late Wednesday afternoon in what is expected to be one of the largest labor actions at the airport in recent years.

The workers for ReadyJet and Flight Services & Systems primarily serve JetBlue Airways and are protesting what they say are threats and intimidation from management as they attempt to organize a union.

The intimidation ramped up over the weekend, according to 32BJ Service Employees International Union District 615, after a strike authorization vote on Friday.

Accompanied by Massachusetts State Police officers, FSS and ReadyJet managers approached groups of workers and told them they weren’t allowed to congregate on the clock.


The workers decided to act quickly with their threatened strike, said 32BJ spokeswoman Amity Paye, “while everyone is strong and before any of those intimidation tactics start to work.”

JetBlue, the largest carrier at Logan and the biggest client of FSS and ReadyJet in Boston, said last week that its subcontractors are preparing extra staffing and it was anticipating a minimal impact.

The two companies’ employees make up the vast majority of JetBlue’s third-party workforce at Logan.

ReadyJet and FSS did not return requests for comment.

Both companies have been fined for numerous wage theft and safety violations at Logan over the years, and the National Labor Relations Board has charged the companies with interfering with workers’ right to organize.

The union filed a new complaint with the labor board on Tuesday over an FSS manager taking photos of a worker talking to a union representative.

The Massachusetts Port Authority, which runs Logan, declined to comment.

A number of local politicians pledged their support to the striking workers, including Mayor Martin J. Walsh, who told them at a rally last week that organizing is “your right as American workers.”


City Councilor Lydia Edwards plans to introduce a resolution to support the strike at Wednesday’s City Council meeting at noon, Paye said, and several of the workers are expected to attend.

The picket line is set to start at 4:30 p.m., during a major shift change of cabin cleaners, and continue indefinitely.

Dayail Gethers, a 35-year-old wheelchair attendant for FSS, will be among those on the picket line. The Hyde Park resident has a 4-year-old daughter to support but said the risk is worth it.

“It will be beneficial in the long run,” she said. “I’ll make better living for my family by standing up for myself.”

Katie Johnston can be reached at katie.johnston@globe.com. Follow her on Twitter @ktkjohnston.