Millions of unskilled migrant workers could be forced to leave this southern boomtown in the face of its continuing industrial restructuring, a local statistician has said.

The lacking skills and general know-how of migrant farmers-turned-workers could make companies unwilling to employ them, Kong Ailing, chief of Shenzhen statistics team of National Bureau of Statistics, said.

Barely half of the more than 8 million of Shenzhen's total 12 million population who come from other areas only finished junior middle school education, and the working background of 56 percent was in the electronics, machinery, furniture, garment, toy, catering and services sectors, according to a recent survey by the statistics team.

Only one percent of this sizable social group in the booming city, the forerunner of the country's reform and opening-up, were actually skilled workers, the survey concluded.

"Workers' poor education could be seen as hampering companies' innovation potential in a city where knowledge and technologies become more and more important," Kong said.

The municipal government allocate resources toward training its migrant workers and also cooperate with some corporations and the communities to satisfy the demands of high-end industries, she said.

"Migrant workers, if better trained and educated, will promote the city's economic growth," senior researcher with Shenzhen Academy of Social Sciences, Yang Lixun, said.

Since setting up its first free training school for migrant workers earlier this year, the local government has set itself the target of training 1 million unskilled workers over the next five years.