TOKYO — Japan's Prime Minister Fumio Kishida has slammed a gathering of ruling party members last November that involved scantily-clad dancers.

Leaked footage of the event, organized by a chapter of the Liberal Democratic Party, showed women in swimwear, reports said.

The event was "highly inappropriate and most regrettable", said Kishida when grilled by lawmakers on Friday.

At least one of the event organizers has since resigned from the party.

The women, who are reportedly part of the Osaka and Kyoto-based Glamor Dancers troupe, were asked to use their mouths to receive banknotes hanging from participants' mouths, claimed local media reports.

The event was attended by members of the Liberal Democratic Party (LDP)'s youth division in the western city of Wakayama.

One of the organizers, Tetsuya Kawabata, had earlier sought to defend the event by saying that the presence of the "go-go dancers" -- referring to dancers employed to entertain crowds in nightclubs -- was intended to ensure "diversity".

"We invited the dancers after studying from various viewpoints, including whether it matches the theme of diversity," Kawabata, deputy head of the local LDP youth wing, told Japanese broadcaster All-Nippon News Network.

The gathering sparked "excitement that... exceeded my expectations", reports quoted Kawabata as saying.

He has now reportedly resigned from the party.

The LDP's nationwide youth wing had earlier apologized and said two other MPs who attended the event would step down from their posts in the division.

On Wednesday, Kishida said the event did not "match the cabinet's goal of diversity".

"What my cabinet seeks is an inclusive society where all people feel the meaning of life with their dignity and diversity respected," local media reports quoted him as saying.

He added that the event was funded by the participants' membership fees, not taxpayers' money.

This is the latest in a string of other scandals that the LDP has been confronted with, most notably one over a fundraising scandal involving the party's most powerful faction.

It also comes at a time when the party is seeking to get more women into the male-dominated world of Japanese politics. Kishida's cabinet now features a record number of five women.

However, his government's approval ratings are at their lowest since the LDP returned to power in 2012. An opinion poll on Thursday showed the approval rate standing at 18% in March. — BBC