Sexist jeers from governing party members repeatedly interrupted a Tokyo assemblywoman during a debate about how to support child-rearing women in a country facing a population crisis.
Ayaka Shiomura, 35, was questioning senior figures in the city administration on plans to help current and future mothers when the abuse erupted from seats occupied by members of Prime Minister Shinzo Abe's Liberal Democratic Party (LDP).
Shouts of "Why don't you get married?" and "Are you not able to have a baby?" could be heard as she spoke, said fellow assembly member Shun Otokita, of Shiomura's opposition Your Party.
Shiomura continued her questioning, despite being reduced to tears during the debate Wednesday, her colleague added.
The Mainichi Shimbun and Asahi Shimbun newspapers both reported the incident.
"The jeering came from the direction of the seats allocated for the LDP members," Otokita told AFP.
Shiomura on Thursday told reporters she had been jeered by more than one assembly member.
"They should not shout things that have nothing to do with policies," she said.
"Jeers like that degrade a person and amount to abuse. They should show respect for an assembly member who stands for questioning."
The incident happened as Shiomura was calling for more support for women who are considering fertility treatment, the Asahi reported.
Japan has one of the lowest rates of female workforce participation in the developed world and most economists agree it badly needs to boost the number of working women.
But a lack of childcare facilities, poor career support and deeply entrenched sexism are blamed for keeping women at home.
- 'Terrible sexual harassment' -
A growing number of women are delaying their decision to have children so they can maintain a career, a factor that contributes to Japan's low fertility rate, which hovers around 1.3 -- well below the replacement rate.
Abe has pledged to increase the number of working women, and has said he would like 30 percent of leadership positions occupied by females by 2020.
The rate is currently around 11 percent in the private sector, and less than that in the public sector. Commentators say Abe's stated target is highly ambitious.
Goldman Sachs earlier this year said Japan could boost its GDP by 12.5 percent if it closed the gender gap, and would add 7.1 million people to a workforce that is currently shrinking and struggling to pay for the pensions of the growing legions of elderly.
Otokita said his party would discuss a formal protest against the abuse Shiomura had faced in the assembly.
Support for Shiomura came from across the party spectrum. A member of the LDP's coalition partner New Komeito said she could "never forgive" the behaviour, while the Japan Communist Party said it was "terrible sexual harassment".
An official at LDP headquarters said the party was still gathering information about the incident and was unable yet to respond to complaints.
The Tokyo Metropolitan Government administers an area that is home to around 13.35 million people, about one-tenth of Japan's population, and has an annual budget of some 220 billion yen ($2.2 billion).
The city assembly has 127 members, of whom 25 are women. In national politics, women occupy just 78 of the 722 seats in the two legislative chambers of parliament.