This combo photo shows South Korean politician Park Young-sun of the Democratic Party (left) and the opposition People Power Party's Na Kyung-won. The two politicians are possible candidates running for the mayoral seat in Seoul. (PHOTOS / AFP AND BLOOMBERG)

The suicide of Seoul’s mayor in the wake of sexual harassment allegations shamed South Korea’s male-dominated society. The April election to replace him is now turning into a battle over women’s rights that could impact the legacy of self-described “feminist president” Moon Jae-in.

His Democratic Party is expected to put up veteran female politician Park Young-sun to try and retain the mayoral seat in Seoul, which is often seen as a springboard to the presidency. Her main challenger is looking to be Na Kyung-won, one of the most prominent female conservative leaders of the main opposition People Power Party (PPP), which has risen in national polls ahead of a presidential election scheduled for next year. The parties will make their official selections in early March.

President Moon Jae-in's Democratic Party is expected to put up veteran female politician Park Young-sun to try and retain the mayoral seat in Seoul, while the opposition People Power Party is likely to field Na Kyung-won, one of the party's most prominent female conservative leaders 

What’s worse for Moon, another member of his party had stepped down last year as mayor of the southern city of Busan after being accused of sexual assault - and was indicted last month. That by-election gives a chance for the conservative opposition to take back the post in a traditional stronghold and deal a blow to Moon’s progressives.

The elections in cities that account for about a quarter of South Korea’s population will be a key a barometer of support for Moon’s progressives as his party seeks to keep the presidency after his single five-year term ends next year. They also serve as a reminder about Moon’s struggles to make progress on women’s issues and turn the page on a series of sexual assault and harassment scandals.

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“If the opposition takes any of the two cities, it would ring alarm bells for the Democratic Party ahead of the presidential election,” said Shin Yul, a political science professor at Myongji University in Seoul.

Moon’s support rate was at 39 percent in a weekly tracking poll released by Gallup Korea Friday, hovering near record lows and providing a worrisome sign ahead of the votes in Seoul and Busan.

South Korea’s gender problems run deep. Despite being the world’s 10th-largest economy, the country has the largest wage gap between men and women of any developed country, according to data from the Organisation for Economic Co-operation and Development. Only three of Moon’s 18 cabinet members are women, and South Korea ranks in the bottom half of the world in terms of female representation in parliament with 17.1 percent.

Difficulties facing women are also have an economic impact. Apart from the wage gap, South Korea’s fertility rate of 0.84 last year was the lowest in the developed world, according to Statistics Korea. This is driving down the potential growth rate. Women have blamed the high cost of raising children, difficulties in returning to the workforce after giving birth and a lack of support for single-parent households.

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The scandals have put Seoul on a course to elect its first female mayor, with women leading the tickets of the two biggest parties ahead of internal votes. There’s also one prominent male contender, Ahn Cheol-soo, from a minor conservative party.

The winner of the April election will serve out the term of Park Won-soon, who killed himself in July in the wake of sexual harassment allegations

The winner will serve out the term of Park Won-soon, who killed himself in July after one of his former secretaries filed charges against him for what she said was inappropriate physical contact and obscene images sent to her phone.

Na has slammed the ruling party for using gender as a “political tool” to score votes without making any practical progress on gender inequality. The assaults by the former mayors revealed South Korea’s “structural violence” against women, she said last week.

“Progressives had been more vocal about gender equality and women’s rights,” Na said in a written response provided by her office to questions on the election. “Ironically though, it was progressives that have demonstrated sexual misconduct when they were in office.”

Na wants to replace opaque walls in the offices of high-ranking city officials with glass to prevent misconduct at the workplace, and also set up a housing evaluation system in Seoul to certify real estate as having measures to prevent sexual assault.

READ MORE: #MeToo battle continues in S. Korea, 2 years after first case

Park Young-sun and her office didn’t immediately respond to requests for comments. Her office said that Park plans to announce her plans for gender equality “soon.” Officials at the presidential Blue House referred a request for comment to the Gender Equality Ministry. The ministry said it has been implementing “appropriate measures” to tackle the country’s growing gender inequality, noting it set up a Department of Gender Equality Policy in eight ministries.

Moon has promised to do more. His Gender Ministry recently announced a new push to prioritize preventing sexual crimes against women in its year-ahead plan, which included plans to research stalking and date rape.

Cho Eun-hee, another possible female candidate with PPP in the Seoul race, viewed the government’s gender equality policies as window dressing.

“It talks about values of democracy and human rights, but in my eyes it’s all fake,” Cho said. “Nothing more than rhetoric.”