BEIJING • China is making a new push to raise one of the world's lowest retirement ages as it tries to cope with a rapidly ageing population, a move that is already fuelling discontent and will test the Chinese Communist Party's ability to implement reforms.

The ruling party alluded to the change last month when it released an outline of its five-year economic plan, which included a recommendation to "implement postponing the retirement age". Specific measures in the plan are due to be unveiled next March.

China's retirement age has remained unchanged for more than four decades at 60 for men and 55 for female white-collar workers, even as life expectancy has risen. In places like Japan and Taiwan, most men and women can retire and start drawing a pension at 65.

The party's statement produced a fierce backlash domestically, with tens of thousands of angry comments posted on Weibo, China's equivalent of Twitter.

Top among the complaints were from those closest to retiring, expressing anger at the prospect of delayed access to their pensions.

Younger people argued that an increase in the number of older workers would reduce their employment opportunities.

Experts say raising the age at which workers are eligible for state-supported pensions is crucial to ensure the sustainability of the retirement system. The Chinese Academy of Social Sciences, a government think-tank, estimated in a report last year that the main pension fund for urban workers will peak at 7 trillion yuan (S$1.4 trillion) in 2027, before falling to zero by 2035. The balance last year was 4.3 trillion yuan.

Raising the retirement age would also help China maintain economic growth, by slowing the rate at which the working-age population shrinks due to falling birth rates. Beijing estimates the number of people aged 60 or more will approach 487 million by 2050, against 254 million last year.

China experienced a baby boom in the early 1960s, resulting in more than 200 million people who will reach 60 in the next decade. As a result, Chinese leaders will have no option but to raise the pension age during the next five-year plan that begins next year, said demographer Wang Feng of the University of California, Irvine.

"A massive number of people will reach this age during the next five years," he said. "If they don't act now, that would impose a tremendous fiscal burden."

BLOOMBERG