A group of Chinese legislators are pushing for a relaxation of the country's family planning policy, arguing it is inappropriate to the times and causes economic and social problems.

Deputies to the National People's Congress have stirred a debate with dire warnings of the consequences of continuing the one-child law.

Professor Wang Ming, of the School of Public Policy and Management of Tsinghua University, said: "If the one-child policy continues, China's imbalanced population structure and aging population will strike a deadly blow to the country's long-term economic growth."

China has been an aging society since 1999. The population over 60 reached 160 million at the end of 2009. The figure is expected to hit 300 million by 2020, accounting for 16.7 percent of the total population.

"China will face severe problems caused by an aging society, including soaring demand for medical care, mounting pressure on retirement systems and labor shortages if we don't adjust the family planning policy," Wang said.

Zhao Linzhong, chairman of the board of directors of Furun Group, said: "China's family planning policy has successfully curbed excessive population growth in the past three decades. Now China's population reproduction picture has been turned around, so we don't have to keep such a strict policy."

Zhao suggested the government change the one-child law to allow all couples to have a second child.

China implemented a policy of family planning to control population growth in the 1970s, under which urban families were allowed just one child, but rural families were allowed a second child if the first was a girl.

Yet some deputies voiced doubts about proposals to relax the family planning rules.

Wu Haiying, director of the Population and Family Planning Commission of Ningxia Hui Autonomous Region, said it was unfair to blame the family planning policy for all problems caused by an aging society.

"Population aging is not as terrifying as some people think. As long as we take active measures to cope with it, elderly people will enjoy good living conditions, enhanced medical treatment and a comfortable retirement," she said.

The family planning policy had prevented more than 400 million births since its implementation, and any easing would result in a rise in population, posing challenges to employment and the environment, said Wang Zaiyin, director of the Population and Family Planning Commission of Sichuan Province.

Labor shortages were the major concern of deputies who proposed to adjust the family planning policy.

China's southeastern provinces have frequently seen shortages of migrant workers in the past decade. Many factories in China's coastal areas have been short-handed since the beginning of the year.

"Due to the one-child policy, China's work force will drop gradually after 2015. The labor shortage may drive up wage costs, weaken competitiveness of China's exports and hinder economic development," Wang Ming said.

Cheap labor has long been considered an important factor in maintaining China's rapid economic growth. Economists call it the "population bonus."

However, some delegates argue that labor shortages will help transform labor-intensive factories into high-tech industries.

"This is a good chance to help accelerate the transformation of China's economic growth pattern," said Cheng Enfu, director of the Academy of Marxism of Chinese Academy of Social Sciences.

"I don't think the supply of workers really falls short of demand in China. Some migrant workers have chosen to stay in rural areas because they found farming was more profitable than before. Those companies that are short of workers should come up with new strategies to attract them back," he said.