Drivers for the city's three bus companies are demanding an 8 per cent pay rise this year to keep pace with inflation.
Their unions also want the daily pay for casual drivers to rise by HK$40.
Chung Kin-wa, of the Motor Transport Workers General Union, said the demands were based on inflation and the bus firms' profits.
'We're asking for an 8 per cent pay rise because prices in the city keep increasing. If you walk into any restaurant or supermarket, you will easily feel the pain of inflation,' Chung said.
He said that as socially responsible businesses, bus companies should share the profits with their staff. 'The bus companies are all making profits, so the staff should be entitled to share them,' he said.
Last year, the union called for a salary increase of between 7.5 per cent and 8 per cent, but all drivers were eventually given a 4 per cent rise. Chung said: 'The rise failed to keep pace with inflation as the [inflation] rate announced by the government was over 5 per cent.'