A 31-year-old feminist politician joined the campaign of main opposition presidential nominee Yoon Suk-yeol on Monday in a surprise move expected to widen the conservative candidate's appeal among young female voters.

Shin Ji-ye, a vocal feminist who currently heads the non-profit Korean Women's Political Network, was named senior deputy chair of the Saesidae Preparatory Committee, an organization that works directly under Yoon to woo moderates and liberals with an affinity for the conservative People Power Party. "Saesidae" means "new era."

Shin entered politics in 2004 as the leader of a youth movement that demanded the removal of guidelines on student hairstyles at schools. In 2016, she ran for a seat in the National Assembly as a proportional representation candidate of the Green Party.

Most recently, she ran as an independent in the Seoul mayoral by-election in April.

Shin has been vocal about the need to enhance women's rights and recently called for the creation of a women voters' alliance ahead of the March presidential election.

Her decision to join Yoon's campaign came as a surprise because she has often clashed bitterly over gender issues with PPP Chairman Lee Jun-seok, who has advocated for anti-feminist male voters in their 20s.

At a welcome event held for her at the committee's office on Monday, Shin admitted there were many things to consider before deciding to help Yoon's campaign.

"(Yoon) promised to resolve violence against women, address the climate crisis and create a Republic of Korea that overcomes (the division of) left and right and moves forward, so I decided to take part," she said. "I plan to help out a lot in order to open a new era."

Yoon, who also attended the event, said he disagreed with concerns that appointing people of differing creeds will hurt the PPP's identity.

"It's when people with different thoughts come together inside the same political party to debate and reach a decision that the party will be able to realize democracy," he said. (Yonhap)