The government did revise the one-child policy in late 2013, allowing couples to have two children if either parent was an only child. However, the impact was underwhelming, with only 1.6 million couples, out of the 11 million who were eligible, applying to have a second child by July this year.

"People are making their decision to have one child not because of the family planning policy but because the costs involved are now higher and there is a huge amount of focus on education, requiring special attention," said Zuo Xuejin, a demographics researcher at the Shanghai Academy of Social Sciences.

He expects a new two-child policy to come into force from next year and says within five years all controls will likely be removed.

Fertility rate

China's fertility rate sits at around 1.5, well below the replacement level of 2.1 and one of the lowest in the world. In the bigger cities, it is closer to 1.

Meanwhile, its working-age population is shrinking and its dependency ratio is increasing. The number of people aged 65 and over was 137 million last year, just over 10 per cent of the population and that's expected to jump to 30 per cent by 2050, according to the United Nations.

All of these statistics mean that China is losing the demographic dividend that helped fire its economy on double-digit growth rates for three decades. The Chinese government argues the controversial policy lifted hundreds of millions of people out of poverty.

But critics say it also resulted in tragedy with an increase in female infanticide and cases of horrific forced abortions.

In recent years, even government-related think tanks have lobbied for a change and in the lead up to the formation of the latest five-year plan a group of researchers, including those from the Chinese Academy of Social Sciences and Renmin University, submitted a report to authorities calling for an immediate relaxation.

"We have to make some changes so that China is prepared for a rapidly aging population," said Mr Zuo. "We need to make the pension system more sustainable and expand its coverage so that it covers migrant workers. We need to make the population healthier and encourage people to have more children with supporting policies."

Policymakers will gather in Beijing next week for the Communist Party's so-called "Fifth Plenum" and some time after that the new five-year plan will be released. It will also include guidance on economic growth and a suite of new proposals to address air, water and land pollution.