Beijing, July 24 - Couples in China's glittering metropolis of Shanghai are being encouraged to have another child to overcome an ageing population due to the decades old strictly enforced one-child policy norm, an official said.

'We advocate eligible couples to have two kids because it can help reduce the proportion of the ageing people and alleviate a workforce shortage in the future,' Xie Lingli, director of the Shanghai Population and Family Planning Commission, was quoted as saying by China Daily Friday.

Shanghai has more than three million registered residents aged 60 and above, nearly 22 percent of the population. By 2020, the proportion is expected to rise to about 34 percent.

Family planning officials and volunteers will now make home visits and slip leaflets under doorways to encourage couples to have a second child if both have grown up as only children.