For a young mother expecting her second child, concern over whether she can find a day care facility is causing extra stress.

“I’m worried about whether I’ll be able to find a slot by the time I return to work,” the 34-year-old office worker said as she played with her 6-year-old son in a park in the city of Oita.

There were 350 children on the waiting list for day care facilities in Oita as of April 2016, the eighth-largest figure in the nation. The number rose to 463 this spring.

In total, the nation’s waiting list stood at 23,700 as of April.

Prime Minister Shinzo Abe once pledged to cut the waiting list to zero by the end of next March as part of a strategy to get more women to enter the workforce. But in May, he postponed the target by three years, citing an increase in the number of working mothers resulting in higher demand for child care.

Critics and some lawmakers, including from the ruling camp, are skeptical about the feasibility of the goal — even with the three-year extension.

In Oita, a city official attributed the local day care shortage to a population increase.

“People are coming in from other municipalities in Oita Prefecture and the population has been concentrated in one area,” the official said, citing areas around Oita Station where many apartments are being built. “Demand for day care is rising.”

The problem of population concentration is shared by many other prefectural capitals.

The Oita Municipal Government plans to add 941 day care slots this fiscal year, more than double the previous year.

“The central government has postponed the target (of reducing children on day care waiting lists to zero) to the end of fiscal 2020, but our city aims to attain the target next April,” Oita Mayor Kiichiro Sato said.

Sato said Oita needs to enhance child care services to maintain its population, even if doing involves a huge financial burden.

Government efforts to tackle the shortage began in 2001 after then-Prime Minister Junichiro Koizumi pledged during his inaugural policy speech to address the issue.

“Raising the issue during his first Diet speech reflected Mr. Koizumi’s political savvy,” said Mariko Bando, chancellor of Showa Women’s University.

Bando, who was then director of the Cabinet Office’s Gender Equality Bureau, said that at the time, many Japanese believed mothers should stay at home until their children turn 3.

“Day care was thus considered a necessary evil,” she said.

Several years after Koizumi raised the issue, day care spots increased by 25,000 to 30,000 annually. The number of children on waiting lists fell from 25,000 in fiscal 2002 to 18,000 in five years.

In fiscal 2007, however, capacity growth began to slow and waiting lists got longer.

Bando attributed the slowdown to conservative forces in the ruling Liberal Democratic Party gaining strength again. Many of these conservatives advocate women staying home.

The trend was prominent after Abe replaced Koizumi in 2006 in his first term as prime minister, she said. Abe quit his first stint in 2007, but after returning to power in 2012, he changed his stance and began to advocate adding more women to the workforce as part of his growth strategy.

But a major obstacle to increasing day care capacity is a shortage of day care workers.

“We have to know that it takes time to develop human resources,” said Konan University professor Masako Maeda, who served as Yokohama’s deputy mayor from 2003 to 2007. The city is known for ambitious efforts to overhaul its child care system.

Maeda said building day care centers at a rapid pace has caused a vicious cycle. A lack of staff leads to increased overtime and quitting due to exhaustion, and the tough working conditions put off potential recruits.

“When we built the centers, we should have trained a sufficient number of workers, too,” Maeda said.

The slow improvement has generated frustration and outrage among working mothers.

In February 2016, an anonymous blog titled “I couldn’t get day care — die Japan!” went viral. It prompted a protest over the shortage among working parents in front of the Diet building in Tokyo. The opposition camp also called for action.

Some veteran lawmakers in the ruling camp, however, appeared to be taken by surprise. “It used to be only natural that a mother would quit her job to deliver her baby, and would never get so furious about day care,” said an LDP lawmaker who served in a ministerial post.

Konan University’s Maeda said tax revenue must be used to increase wages for day care workers.

“Taxpayers should also brace for a burden,” Maeda said.