Japanese couples who decide not to have children are “selfish”, a senior politician has said amid a push by the government to increase the country’s birth rate.

Experts are warning of a “demographic time bomb” in Japan, with the population set to dramatically decline in the coming decades due to a low fertility rate and an increasing number of people living longer.

The issue has forced the prime minister, Shinzo Abe, to vow to raise the birth rate and increase the number of women in the workplace, in an attempt to stave off what could become an economic crisis.

“During and after the war when [people] were living on the edge of starvation, nobody said it’s better not to have children because it would be too much trouble,” Toshihiro Nikai, secretary general of the ruling Liberal Democratic Party (LDP), said during a speech in Tokyo.

He added: “These days, some people have a selfish idea that it is better not to give birth to children. In order for everyone [in Japan] to be happy, we should have many children and develop our country.”

The 79-year-old's comments come amid struggles by the government to make good on Mr Abe’s promise to meet demand for childcare places.

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In a recent poll, 70 per cent of parents said they would like to have more children, but felt having larger families would lead to financial worries and a worse work-life balance.

A Japanese think tank estimated there were 340,000 children unable to gain admission to childcare facilities, according to The Japan Times.

Ageing Japan: Robots' role in future of elderly care Show all 15 1 /15 Ageing Japan: Robots' role in future of elderly care Ageing Japan: Robots' role in future of elderly care Residents follow moves made by humanoid robot 'Pepper' during an afternoon exercise routine at Shin-tomi nursing home in Tokyo. Reuters Ageing Japan: Robots' role in future of elderly care Funabashi Hiroshi from A Fun, repairs broken'AIBO's, pet dog robots, at his office in Kasama. Reuters Ageing Japan: Robots' role in future of elderly care A caretaker wearing a 'HAL for care support' robot suit pushes a wheelchair at Shin-tomi nursing home in Tokyo. Reuters Ageing Japan: Robots' role in future of elderly care Residents follow moves made by humanoid robot 'Pepper' during an afternoon exercise routine at Shin-tomi nursing home in Tokyo. Reuters Ageing Japan: Robots' role in future of elderly care Yoichi Suzuki spends time with 'AIBO', a pet dog robot, which his father used for his rehabilitation at his house in Takahag.i Reuters Ageing Japan: Robots' role in future of elderly care A resident approaches humanoid robot 'Pepper' to pat its head during an afternoon exercise routine at Shin-tomi nursing home in Tokyo. Reuters Ageing Japan: Robots' role in future of elderly care A caretaker, wearing walking rehabilitation equipment 'Tree', helps a resident with his walking training at Shin-tomi nursing home in Tokyo. Reuters Ageing Japan: Robots' role in future of elderly care Yoichi Suzuki shows 'AIBO', a pet dog robot, to his bed-ridden mother at his house. Reuters Ageing Japan: Robots' role in future of elderly care A broken'AIBO', a pet dog robot, waits for repair in A Fun's office in Kasama, Ibaraki Prefecture, Japan. Reuters Ageing Japan: Robots' role in future of elderly care A resident touches 'AIBO', a pet dog robot, at Shin-tomi nursing home in Tokyo. Reuters Ageing Japan: Robots' role in future of elderly care A resident touches robot seal 'PARO' at Shin-tomi nursing home in Tokyo. Reuters Ageing Japan: Robots' role in future of elderly care Yoichi Suzuki and his wife take care of his bed-ridden mother as 'AIBO', a pet dog robot walks around at his house in Takahagi. Reuters Ageing Japan: Robots' role in future of elderly care A caretaker wearing a motion assist equipment 'Muscle Suit' carries a resident from a bed to a wheelchair at Shin-tomi nursing home in Tokyo. Reuters Ageing Japan: Robots' role in future of elderly care 'AIBO', a pet dog robot, which Yoichi Suzuki's father used for his rehabilitation, is seen at Suzuki's house in Takahagi. Reuters Ageing Japan: Robots' role in future of elderly care A resident claps to call 'AIBO', a pet dog robot at Shin-tomi nursing home in Tokyo. Reuters

Last month, another LDP politician, Kanji Kato, caused controversy when he revealed he told newlyweds at wedding receptions they “must raise at least three children”.