Since it opened in 2001, the center has offered free legal advice to more than 41,000 migrant workers in Shanghai and helped 450 of them file lawsuits.

"The number of such cases is increasing by more than 20 percent annually on average. It indicates more migrant workers have learned they can have their rights and interests protected by asking for legal aid," said Guan Minquan, deputy director of the Shanghai Legal Aid Center.

In most cases, migrant workers complained that they were treated unfairly by their employers, he said.

He said most of the complaints revolve around five issues: employers who refuse to sign labor contracts, companies that won't pay compensation to workers injured on the job, those that delay or withhold wages, firms that refuse to pay social insurance fees and those that won't admit they hired the migrant workers.

"Because most migrant workers are not rich enough to file lawsuits, free legal service is important for them," Guan said.

Anyone with a monthly income below 290 yuan (US$35) can apply for legal aid. If the application is accepted, the center will appoint a lawyer to provide free service.

Cai Weidong, a native of Ningxia Hui Autonomous Region, is one of the beneficiaries of legal aid.

After signing a contract to work for a local company, he was diagnosed with a mental disease. The company fired him.

His father, Cai Xinfu, came to Shanghai from Ningxia and applied for legal aid to sue the company.

The court ruled that the company must continue to hire Cai as it is illegal to fire him because he is suffering from a mental disorder.

(Shanghai Daily August 5, 2004)