Cathay Pacific issued a stern warning to its employees on Saturday, ordering them to ignore a call to protest at its offices on Monday at Hong Kong airport because of a court injunction order. In an internal document, Tom Owen, the airline’s director of people, told employees to report to work on Monday “as normal and remain professional”. Owen wrote: “I want to reiterate that the Cathay Pacific Group has zero tolerance for any support of, or any participation in, illegal activities.” The pro-democracy Confederation of Trade Unions (CTU) called for a protest at Cathay City, the operations hub of the city’s flag carrier, after the airline on Wednesday sacked Rebecca Sy On-na , the head of the Hong Kong Dragon Airlines Flights Attendants’ Association. Sy on Thursday said the company’s management questioned her about Facebook posts before she was fired. One of Sy’s posts expressed outrage over the shock resignations of Rupert Hogg, Cathay Pacific’s chief executive, and the airline’s chief customer and commercial officer. “This is white terror by Cathay Pacific trying to silence its employees and erode their freedom of speech,” said Lee Cheuk-yan, the general secretary of the CTU, using “ white terror ” to refer to the alleged suppression of political dissent. “We need to take a stand against the airline on Monday to protect workers’ basic freedoms to speak their mind during off-duty hours,” he said. The Hong Kong Police Force on Saturday verbally declined permission for the protest. The CTU said it will appeal against the decision once it had been formally notified of the refusal. The Airport Authority sought an interim injunction after a peaceful five-day mass sit-in descended into chaos on August 13 and caused the cancellation of 979 flights. Last week, Mr Justice Wilson Chan Ka-shun of the High Court indefinitely extended the court injunction order banning unlawful and wilful obstruction of Hong Kong International Airport and the roads near it. The injunction confined all demonstrations to two areas in the arrival hall and barred anyone from “inciting, aiding and/or abetting” any obstructive act. The order did not name the roads near the airport that cannot be blocked. Cathay Pacific noted, in a statement released on Saturday, that the injunction covered Cathay City because its facilities were “absolutely critical” to flight operations . The statement said: “Any activities that impact our ability to operate safely not only significantly disrupt the travelling public, but also jeopardise the safety of our customers and our employees.” Owen, in the internal memo, said workers should also refrain from publicly showing support for the company over concerns that such actions would “exacerbate the tensions and breach the injunction”. Sy was the latest of 14 aviation professionals who were sacked or had resigned after Beijing stepped up pressure on local companies to take a stand against the anti-government movement sweeping the city. The Civil Aviation Administration of China cracked down on Cathay Pacific two weeks ago, banning its any of its staff who had joined unlawful protests in the city from flying into and over mainland airspace, among other measures.