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.