AMERICAN multinationals such as McDonald's encounter few legal barriers in the United States or internationally to using 'sweatshop' labour abroad but face a growing consumer backlash, according to lawyers and labour rights activists. They said the corporate giants, especially fashion and footwear labels like Nike, had responded by drawing up codes of conduct for contractors to follow. But the codes were just a 'tool to please customers' and had no real effect in improving the situation for exploited workers on the mainland, said May Wong Yuet-may, project co-ordinator of the Hong Kong Coalition for the Safe Production of Toys. Sweatshops were usually run by contractors supplying goods to the multinationals as contractors or subcontractors, she said. Those factories were usually owned by foreign investors from Hong Kong, Taiwan or South Korea. China's labour laws were strict but problems arose with a lack of enforcement, especially at foreign-owned factories, Ms Wong said. The mainland sets a minimum working age of 16, but the minimum wage varies in different parts of Guangdong province. Hong Kong does not have a minimum wage. 'We are asking multinationals to follow China's labour laws. All those codes of conduct as far as we know are not as detailed as the Chinese labour law,' Ms Wong said. McDonald's has told non-governmental organisations that it had developed a code but the hamburger chain refused to divulge its contents, said Parry Leung Pak-nang, researcher at the Christian Industrial Committee. A commercial lawyer for a United States firm based in Hong Kong said he was not aware of US laws that would prohibit the import of goods made in sweatshops. The only prohibition was against goods made by forced labour in prison.