The method these labor-intensive manufacturing industries used to win in global competition has hastened the exhaustion of the young, rural workforce, he said.

Only by raising salaries for migrant workers can middle-aged labors be lured back to cities to solve the labor shortage, he said.

But many insiders and experts are not convinced of Zhang Zheng's view.

Xiang Suming, owner of Zhonghe Shoe Co Ltd in Taizhou in East China's Zhejiang province, said: "The main reason for worker scarcity is that the new generation of migrant workers are fairly well educated and they have higher salary and welfare expectations, so many of them frequently change jobs."

That has made many enterprises paying low wages experience a shortage, he said.

Wu Guobao, an expert with the institute of rural development at Chinese Academy of Social Sciences, said: "It's not accurate to say China's young labor in the countryside is exhausted because a large number of young people still choose to stay at home."

The living cost in cities is high while the pay for migrant workers is comparatively low, so employment in urban areas does not necessarily entice all young people in the countryside, he said.

"Therefore, to some extent a labor shortage could only prove that there is a decreasing young, rural labor supply, but it could not prove a labor exhaustion."