China is considering changes to its one-child policy, a former family planning official said, with government advisory bodies drafting proposals in the face of a rapidly ageing society in the world's most populous nation.

Proposed changes would allow for urban couples to have a second child, even if one of the parents is themselves not an only child, the China Daily cited Zhang Weiqing, the former head of the National Population and Family Planning Commission, as saying on Wednesday.

Under current rules, urban couples are permitted a second child if both parents do not have siblings. Looser restrictions on rural couples means many have more than one child.

Population scholars have cited mounting demographic challenges in their calls for reform of the strict policy, introduced in 1979 to limit births in China, which now has 1.34 billion people.

Zhang said the commission and other population research institutes have submitted policy recommendations to the government.

Zhang, who serves on China's congressional advisory body, said any changes if adopted would be gradual.

"China's population policy has always taken into account demographic changes but any fine-tuning to the policy should be gradual and consider the situation in different areas," China Daily cited Zhang as saying.

The relaxed policy might be implemented first in "economically productive regions" and places that have followed closely existing regulations, the paper said.

ABORTIONS, TENSION

President Hu Jintao dropped a standard reference to maintaining low birth rates in his work report to the ruling Communist Party's five-yearly congress in early November, a break which some experts see as evidence of an imminent change to the one-child policy.

Demographers warn that the policy has led to a rapidly graying population that could hamper China's economic competitiveness.

Critics say it also has fuelled forced abortions and increased social tension stemming from an imbalance in the number of boys and girls.

Though forced abortions are illegal in China, officials have long been known to compel women to have the procedures to meet birth-rate targets.

This year, debate over the country's strict family planning rules erupted after a woman in the northwestern province of Shaanxi was forced by officials to have an abortion after seven months of pregnancy.

A growing number of experts expect a change to the policy, partly because of the demographic imbalances it is causing.

And some say the policy is no longer necessary because the cost of raising children in an increasingly prosperous society is already holding down birth rates.