On Beijing Topic List: One-Child Policy's Future .

China's controversial "one-child" policy has once again come up for discussion during the annual meeting of the country's legislature and its top political advisory body, according to local media reports.

Demographers and economists have used the simultaneous meetings for several years to submit proposals for reviewing or relaxing the policy, which was introduced in 1980 to try to control China's population growth.

Critics say the policy—which limits most, though not all, couples to one child—has created a severe gender imbalance, because of a traditional preference for male offspring, and a rapidly aging population which threatens China's long-term economic growth.

The government had originally said the policy would only last three decades, and many observers had expected it to be reviewed around the time of its 30th anniversary last year.

However, the National Population and Family Planning Commission said in December it planned to keep the policy largely the same for the next five years, and has not indicated what might happen after that. Some officials still see the restrictions as key to holding down population growth, and therefore unemployment and strains on resources.

The policy has long allowed exemptions for significant portions of China's population, including many rural families, ethnic minorities and couples where both people are only children themselves.

But most families in urban areas still have to pay fines if they have more than one child. Those who dodge the fines cannot register their children for public services, including state education and health care.

One proposal under consideration is to introduce a "two-child" policy nationwide, according to a report on the web site of the People's Daily, the Communist Party newspaper.

It quoted Wang Yuqing, a member of the Chinese People's Political Consultative Conference, or CPPCC—a powerless advisory body that is meeting this week alongside the annual session of China's legislature, the National People's Congress—as saying he thought there would be such a change by 2015.

Mr. Wang, who is a deputy director of the CPPCC's National Committee of Population, Resources and Environment, also said he didn't think such a move would lead to rapid population growth, according to the report.

Mr. Wang couldn't be reached directly for comment Tuesday, and the Family Planning Commission did not respond to a request for comment.

However, other Chinese experts have said they expect a clearer picture could emerge after further discussion over the course of this week. The legislative session ends Monday.