A feud in the ruling Grand National Party over candidate nomination rules deepened Wednesday, with some of its defiant lawmakers threatening to take no-confidence action against the party leadership led by Rep. Park Geun-hye.

Rep. Chang Je-won stepped up pressure on two key members of the GNP leadership council ― Kim Jong-in and Lee Sang-don ― calling for them to resign. The two have been calling on old guard members and those close to President Lee Myung-bak to give up the nomination race in the upcoming parliamentary vote in April.

“If the two council members who caused this row do not step down, I will push for collective action against them,” the first-time lawmaker said on the radio. Asked what kind of actions he was thinking, the politician answered a party convention to elect new leadership is one of them.

“Lawmakers who share the same view with me about their resignation will gather and issue a joint statement,” he said. The statement would be out around next Tuesday, he added.

Rep. Chang belongs to the pro-president faction who has been in rivalry with those close to the current party chief Park.

But the defiant mood was not confined to the pro-Lee faction.

Even pro-Park lawmakers did not hide their growing unease toward the party leaders’ drastic drive to revamp nomination rules toward giving no favor to current lawmakers.

Disturbing them most was the revelation earlier this week that their leaders were considering dropping incumbent lawmakers whose approval ratings are more than 5 percentage points lower than that of the party from its nomination race. The 5-percentage point bar is seen particularly tough to meet for representatives from the party’s traditional stronghold in the Gyeongsang provinces and Seoul’s affluent districts south of the Han River, also GNP hometurf.

Rep. Son Beom-gyu, a pro-Park member, called on other pro-Park lawmakers to make “sacrifices” in order to salvage Park’s reforms to regain trust from voters, who brought about the ruling party’s loss in the recent by-elections.

“A reform will not be completed if the chief goes soft on people close to her while being tough on the rest,” he said, urging pro-Park members to give up all their vested rights in the elections.

The first-term lawmaker also said the 5-pecentage point rule was in the right direction.

“If we try to protect incumbents with low approval ratings, the whole party will suffer,” he said.

Council members Kim and Lee showed no sign of retreat in their push to dump the old guard, particularly those from the party’s traditional stronghold in the Gyeongsang provinces.

Kim warned that those who refuse to change will be forced to change. He said the party must bring in fresh faces in order to stand any chance of winning the general elections in April. News media polls show the majority of voters in constituencies prefer new candidates to incumbent lawmakers for the next National Assembly.

Park took the helm of the GNP late last year with promises to fundamentally remake the moribund party. She hinted Tuesday at drastic changes in the process to nominate candidates, saying the party needs to change the “content,” not just the package, to restore voter trust.

By Lee Sun-young (milaya@heraldcorp.com)