More than 50 union workers at Newark Liberty International Airport rallied on Thursday ahead of the busy Fourth of July travel weekend to protest United Airlines’ plans to change its labor standards.

The Service Employees International Union says the airline is cutting standards for 600 cabin cleaners and lift truck drivers.

The airline announced plans to convert 80% of its 600 full-time positions to part-time, end workers’ employer-paid health care and cut citizenship support.

In response to the protest, a spokesperson for United issued the following statement:

“United is moving aircraft cleaning at Newark to United Ground Express in October. UGE has already made conditional job offers to all Prospect employees to fill full-time and part-time roles paying more than $25 per hour and represented by the International Association of Machinists & Aerospace Workers. UGE is working closely with Prospect on this transition and they have been communicating to Prospect employees to make sure they understand their options.”