It admitted breaches of the labour laws and was fined $36,000 in a Labour Department prosecution in May.

But efforts by the workers to get the money they claim they are owed have been fruitless.

Cleaning Workers Union organiser Chan Po-ying said the authority should confiscate the company's $306,000 performance guarantee deposit, which it is still withholding, and pay it to the workers.

'The contract stated that the operator should obey the labour law, and now it's been violated.'

The company gave the 43 workers it hired during the six years only two days off a month and seven days' annual leave, in breach of labour laws which stipulate a rest day every seven days and annual leave according to length of service.

All the authority had done so far was suggest they apply to the Protection of Wages on Insolvency Fund, but they did not want to do that as it would not give them full compensation, Ms Chan said.

Dustman Yau Chi-keung, 70, urged the government to cancel the 'flawed' outsourcing policy.

'We questioned the company about the insufficient holiday problem, but they just asked us to quit if we didn't accept it,' he said.

The protesters waved banners, shouted slogans and handed a petition to authority representatives who said they would reply as soon as possible.

Ms Chan said they would seek help from legislators if the authority did not give them a satisfactory result in a week.

The Housing Authority said it could not use the bond directly to pay the workers, but if the company went bankrupt, workers could seek the money through receivers.

The authority also said it would work with the Labour Department to solve the problem.