The union will hold a rally at 4pm at Edinburgh Place in Central, to protest against recent staff dismissals by the airline.
Beijing has told Cathay that staff who support anti-government protests won’t be allowed to fly into mainland airspace.
Talking to RTHK’s Hong Kong Today, Carol Ng said the airline needs to face these workers, who she says have been terminated without proper reason.
“People are now saying this company no longer belongs to Hong Kong. They’re actually controlled by someone… perhaps mainland China,” Ng said.
“One of the very important images for an airline is your professionalism, but if you’re giving up your professionalism you will gradually lose the trust and confidence of your customers,” she said.
“And it’s an actual fact, when there is a large amount of theses experienced flying staff being dismissed; what’s going to happen in their operational safety?”
The Hong Kong carrier has warned staff against supporting any “illegal” anti-extradition protests, violent action or overly radical behaviour, on social media – even outside work hours.
The airline said it was adopting a zero-tolerance approach in order to fulfil the the conditions recently imposed by Beijing’s aviation regulator, which has barred its flights from mainland airspace if they carry staff who have taken part in the protests.
Two senior Cathay executives, including CEO Rupert Hogg, have resigned in the wake of the mainland’s intervention.