Couples in Shanghai barred from having a second child have drawn encouragement from comments by a family planning authority chief that they should be allowed to have another baby if they wish.
On the mainland, couples in which both partners are from one-child families are permitted to have a second child, but if one or both partners have a sibling they are restricted to a single child.
Breaching the rule usually results in fines of tens of thousands of yuan, loss of jobs if the parents work in government or state-owned enterprises, or even forced abortions, like the one a woman seven months pregnant endured this month in Shaanxi province.
Guangdong applied to the central government last year for permission to institute a pilot programme that would allow couples in which only one partner was from a single-child family to have a second child.
But Sun Changmin, vice-director of the Shanghai Population and Family Planning Commission, told the Oriental Morning Post on Tuesday such a pilot programme was not necessary. All couples, including those in which one or both partners had siblings, should be allowed to have a second child, Sun said, and suggested the change come 'when the time is ripe'.
The central government often claims its birth-control policy has resulted in about 400 million fewer people being added to the national population over the past 30 years. But, faced with ageing society, there is a growing number of advocates, from academia and the government, for lifting the restriction.
Sun did not give a timetable but said the key task for the government was to research how many families were willing to have a second child, how many were prepared to have only one child, and how many preferred to have double incomes with no children. The authorities should also identify what factors encouraged or deterred couples from starting a family.
Sun said checking whether a parent was from a single-child family, as the pilot programme would require, would only add to administrative costs.
In Shanghai, the city with the fastest-ageing population on the mainland, 24 per cent of its 14.2 million permanent residents are aged 60 years or over, according to the municipal civil affairs bureau.
The Oriental Morning Post surveyed 829 Shanghai residents three years ago and found half were not interested in having a second child, mainly due to the costs. Of the people who are permitted to have a second child, less than one fifth said they were likely do so.
Sun said it was difficult to raise the fertility rate in most cities. Couples who tended to have more children were concentrated either in poor rural areas where the social security network was absent, or in southeastern coastal regions where wealthier people held to a traditional belief favouring a bigger family.
Last month a couple in Wenzhou in Zhejiang was fined 1.3 million yuan (HK$1.6 million) for having a second child. The city has seen about 20 incidents in recent years of wealthy couples paying huge fines for violating birth-control rules.
In Shanghai some people privately say enforcement of the one-child policy has grown slack and that if couples have a second child at least five years after the first, they will not attract attention from the authorities. Others say registering the two children's permanent residence (hukou) separately in two households will also help parents avoid penalities.
The forced abortion in Shaanxi caused wide outrage after pictures of the fetus beside the mother were posted online. Provincial family planning authorities have ordered local officials to punish those involved in the late-term abortion.