The top family planning official has warned that the world's most populous country could face a "population rebound" because the newly rich are ignoring population control laws and because of early marriages in rural areas.

The family planning policy, implemented in the late 1970s, limits most urban couples to one child and rural families to two in an attempt to control population growth and conserve natural resources.

But rising incomes mean some newly rich families can afford to break the rules and pay the resulting fines, while the traditional desire for sons encourages some rural families to also flout the rules.

In response to the widespread rule-breaking, Zhang Weiqing, director of the National Population and Family Planning Commission (NPFPC), said the country's currently low birth rate may be unsustainable and that the risk of a "population rebound" was very real.

"Early marriages are still prevalent in some parts of the country, especially in rural areas, which goes against the family planning policy," said Zhang.

According to the Constitution, men may marry at the age of 22, and women at 20. The country's family planning policy, which has been in place since the 1970s, encourages late marriages and late childbearing.

However, Zhang said, the widening wealth gap had challenged the country's family planning efforts as wealthy people simply ignored the decades-old one-child policy and paid to have as many children as they wanted.

The number of rich people and celebrities having more than one child has been increasing rapidly, and nearly 10 percent of the people in this group have three, according to a recent survey by the NPFPC.

Zhang said young couples who were born in the 1970s and 1980s and raised as only children are also allowed to have second children, which had contributed to the rising birth rate in some central and western provinces.

The NPFPC will continue to offer preferential services to couples who abide by the family planning policy, Zhang said, adding that the government would increase its spending on family planning to 30 yuan (US$3.80) per person during the 11th Five-Year Plan period (2006-10).

China has been following a strict family planning policy to contain its population growth.

China has about 1.3 billion people, 20 percent of the world's total. The government has pledged to keep the population under 1.36 billion in 2010, and under 1.45 billion in 2020.

(China Daily via Agencies May 8, 2007)