The performance at the conservative Liberty Korea Party's 'Woman Festa' saw five party supporters on stage pull down baggy long shorts and bend over to display the phrase 'Victory for LKP' written on boxer shorts

An event to promote women's rights in South Korea featuring female opposition party supporters pulling down their shorts has drawn widespread criticism, with many saying the stunt revealed a patriarchal culture in the party and Korean society generally.

Despite its economic advances, South Korean society remains highly male-dominated and its gender pay gap is the highest among developed countries, with working women only making 63 percent of what men earn.

Female lawmakers constitute less than a quarter of the 300-member legislature.

The performance at the conservative Liberty Korea Party's "Woman Festa" saw five party supporters on stage pull down baggy long shorts and bend over to display the phrase "Victory for LKP" written on boxer shorts.

They wiggled to a cheering audience including former prime minister and party leader Hwang Kyo-ahn and parliamentary floor leader Na Kyung-won, who is a woman.

Hwang called on them to "practise more" in encouragement, South Korean broadcaster YTN reported.

Public outcry was swift, with one internet user saying, "even elementary school students would not stage such childish stunts."

The LKP put out a statement saying the performance was not intended to degrade the women, adding it was not aware of the stunt beforehand.

"We regret the controversy is damaging the party's efforts to recruit female talent," it added.

The incident "acutely" shows the LKP's culture towards women, rights activist Bae Bog-joo told AFP.

"Women were mobilised with their bodies as tools in the name of raising party morale," she said.

"The fact that no one was troubled by it shows how the party sees women's roles in the organisation."