Flight attendants at Hong Kong airline Cathay Pacific Airways are threatening to withhold food, alcohol and even smiles from passengers during the Christmas holidays over a pay dispute, a union official said on Thursday.

Cabin staff at the airline, which has a reputation for top-notch service, voted at a union meeting this week in favor of industrial action that could also result in flight delays.

The union is demanding a 5% pay increase but the airline, which is struggling to cut costs after posting a first-half loss of 935 million Hong Kong dollars ($120.5 million), has offered 2%.

The Cathay Pacific Airways Flight Attendants Union will soon announce when the action approved in the vote will be carried out, General Secretary Tsang Kwok-fung said.

"We may not provide alcoholic drinks to our passengers, or we may not even provide meals to passengers," in which case the union would advise travelers to bring their own food and drinks, said Tsang.