HONG KONG - Hundreds of workers in Hong Kong called for a minimum wage law Wednesday as lawmakers debated the controversial issue which has long divided the city's business sector and grassroots labour groups.

The protesters, many of whom are paid as little as two or three US dollars an hour, said Hong Kong's policymakers and business sector have sacrificed them in the name of competitiveness and preserving the city's free economy.

"We are workers! We are not slaves!" a group of Filipino and Indonesian domestic workers chanted outside Hong Kong's legislature building as lawmakers began the debate on the minimum wage bill.

"Ironically, Hong Kong is now discussing the road to democracy. But how can there be democracy if workers' interests continue to be attacked by the big businesses?" said Eni Lestari, of the Asian Migrants' Coordinating Body.

Labour rights groups have pushed for the minimum wage to be fixed at 33 Hong Kong dollars (4.2 US dollars) an hour, saying anything less would not cover basic expenses with living costs having risen sharply in recent months.

But the proposal faced strong opposition from some of Hong Kong's largest employers.

Michael Chan, chairman of giant fast-food chain Cafe de Coral - who was ranked by Forbes magazine as the 35th richest man in Hong Kong in 2009 - has said his group might issue a profit warning if the proposed hourly rate became law.

Chan's comments have intensified anger among the unions, which have demanded that he quit the Provisional Minimum Wage Commission, a government-appointed body tasked to set the minimum wage once the bill is passed.

Peter Tsoi, a security guard who works more than 12 hours a day, said he had to apply for welfare because he was only paid three US dollars an hour.

"All of my salary is spent on transportation and food," Tsoi told AFP.

"It is easy to understand why Hong Kong has one of the world's widest income gaps between the rich and the poor - the tycoons will only get richer because they are making us work harder and for longer hours while our wages remain unchanged."

A survey released this week showed that supermarket giants Park'n Shop and Wellcome, as well convenience stores Circle K and 7-Eleven, paid their workers an average rate of less than three US dollars an hour.