Two leading Democratic Party figures announced they would break their alliance Tuesday, spelling trouble for Sunday’s party convention.

Former floor leader and aspiring chairman Rep. Park Jie-won pledged to withdraw his support for current chairman Rep. Sohn Hak-kyu, amid their ongoing conflict over the left-wing consolidation process.

Park earlier said that he would serve as Sohn’s chief secretary, should he win in the presidential election next November.

“I have so far maintained a positive relation with Rep. Sohn but no longer feel the need to do so,” Park said in a radio interview on Thursday.

“From now on, I shall stay of out Sohn’s political plans.”

The announcement is expected to be a political blow to Sohn, considering that Park has considerable influence in the Jeolla region.

Park also criticized his former ally for deciding the leadership election rules for the new left-wing party which the DP is planning to form in hand with other liberal groups, in an attempt to raise its chances in next year’s political races.

Sohn and the civic group-based Citizen Integration Party agreed on Wednesday to elect the new leader in the upcoming joint convention on a combined vote of party members and ordinary citizens.

Park nevertheless said that he has no plans to boycott Sunday’s convention or veto the processes.

“Rep. Sohn seems to worry that the in-party vote for integration may end in rejection,” he said.

“I, however, will abide by the decision made by the party in the convention.”

Amid internal backlash, the DP leadership focused Thursday on encouraging its members to participate in Sunday’s convention.

“The upcoming national convention should be held with a festive mood, embracing the long-aspired consolidation,” said floor leader Rep. Kim Jin-pyo.

“We should remember the words of former President Kim Dae-jung, who claimed that unity was crucial for liberal parties.”

By Bae Hyun-jung (tellme@heraldcorp.com)