The factional feud inside the main opposition New Politics Alliance for Democracy is deepening. It is nothing new for the party to be embroiled in severe internal fighting, but this time it is putting the fate of its leader Moon Jae-in in the balance.

Senior party members like former party leader Kim Han-gil and Park Jie-won are openly calling on Moon to step down to take responsibility for the party’s humiliating defeat in the April 29 parliamentary by-elections.

Senior members like Kim and Park are not the only ones raising their voice against Moon. Four deputy secretaries-general of the party demanded that the party leadership resign. About 30 members of the South Jeolla provincial council issued a statement criticizing Moon. Simply put, the party is in chaos.

The root of the latest crisis, of course, lies in the deep rivalry between the party’s mainstream faction led by Moon and other members who had been loyalists of late President Roh Moo-hyun and the minority group based in the southwestern Jeolla region.

Adding fresh fuel to the enmity was a verbal fight between two Supreme Council members over who should take responsibility for the recent election defeat.

Joo Seung-yong, while reiterating his own willingness to step down, said in a meeting of the leadership council last Friday that the entire council should resign.

Jung Cheong-rae, another council member who is well known for his hard-line stance and venomous tongue, disagreed, calling Joo’s expression of willingness to resign as an act of intimidation. He used a vulgar Korean word for intimidation.

An infuriated Joo accused Jung of insulting him, declared that he was resigning immediately and stormed out of the meeting room. Were it not for Jung, this could have been simply seen as another spat that raised the eyebrows of party members and the general public.

But since Jung is a key supporter of the increasingly unpopular pro-Roh faction and is notorious for foul language, the episode became a hot issue. The 30 local council members in South Jeolla Province said in their statement that they were “too ashamed to lift their heads.”

It is indeed more shameful than scandalous to hear from Jung, who shocked many early this year by comparing late presidents Syngman Rhee and Park Chung-hee to Adolf Hitler.

People with sound, sensible judgement may well be fed up with such a politician. A group of 10 rank-and-file members of the party took Jung’s case to the party’s ethics panel, which will start its review Friday. Amid growing outcries, Moon belatedly decided to ban Jung from the Supreme Council meetings.

It would be strange if a party in which people like Jung hold top posts plays its proper role in opposition.

Opinion polls show how the public perceives what the NPAD has been doing and what is happening in the party. The NPAD’s popularity has slipped to 24 percent, compared with 41 percent for the ruling Saenuri Party.

Park Yang-soo, a former lawmaker and a veteran member of the party, called for an extraordinary national convention to replace the party leadership unless Moon and the Supreme Council come up with measures to put its house in order by the end of this week.

It is certain that the NPAD is headed into a grave crisis. Whether it will be able to remain a sizable opposition and eventually become a political force that can take over power from the conservatives will depend on what Moon, rival factions and party members will do to overcome the crisis.