From AP via Inquirer.net:
About 70 percent of China’s estimated 200 million migrant workers have difficulty speaking the national language, Mandarin , though most are required to use it in their jobs, state media reported Monday.
Most prefer to speak in one of the country’s numerous local dialects, and about 70 percent of them found it hard to speak Mandarin, the official Xinhua News Agency said, citing a Ministry of Education report on the country’s language situation last year. China has, at any one time, an estimated 200 million workers in its cities who have migrated from rural areas, according to official statistics. [Full Text]