The trade union's honorary secretary, Michelle Choi, told the South China Morning Post, a regional newspaper: "The blouse is too short and does not cover enough. Whenever a flight attendant bends down, her waistline is exposed."
"We believe the company intentionally does this to make us look a bit sexier and to let the passenger see more," she added.
The tight attire is behind increasing incidents of sexual harassment, according to Chou. She said female flight attendants experience problems on one in every 10 flights.
In addition, Cathay Pacific's frequent flier loyalty program, called the Marco Polo Club, could be aggravating the issue. "Some on the Marco Polo Club members think they can do things to us because they are privileged and we somehow allow it. That is very bad," Chou said.
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"They think it is part of their privilege … afterwards, they believe they can apologize and everything is settled," she added.
However, cabin crew members can now exchange their uniform for a looser, longer option, according to Cathay Pacific. "Crew are welcome to exchange their uniform any time if they feel the fit is not right," the airline told the South Morning China Post in a written response.
It added: "We welcome feedback from the crew and certain modifications have also been made, including the length of the blouse and the tightness of the skirt."