China was once a huge source of economic migrants to other countries. Now there's a reversal - a growing number of foreigners are moving to China to work, attracted by the economic opportunities available. The numbers are now so significant the authorities are drafting the country's first-ever immigration laws to control the number of people coming here from overseas.

The new law is expected to divide potential immigrants into different categories such as skilled and unskilled labor.

In 2007, almost 2.9 million foreigners were registered with the Ministry of Public Security as working legally in China.

That number is rising rapidly. Last year, there were 152,000 foreign resident workers in Shanghai alone, a 14 per cent increase on 2008.