Rep. Lee Sang-jik of the ruling Democratic Party, the founder of the embattled low-cost airline Eastar Jet, said he will leave the party Thursday amid a probe into unpaid wages and mass layoffs at the airline. 

"I will cease to cause trouble for the party and leave it for a while," the two-term lawmaker said in a press conference at the National Assembly.

He also apologized to Eastar employees and the public for causing concern.

"I will do everything to revive Eastar Jet and the jobs of its employees, and faithfully address allegations," Lee said, adding that he plans to return.

The lawmaker has come under growing pressure to take responsibility after the airline announced plans to lay off 605 of its 1,216 employees as part of efforts to attract a new owner.

He is also accused of unjustly transferring his Eastar shares to his children. 

Last week, the DP launched an in-house probe into the allegations and was expected to announce the result before the end of this month. Several members of Lee's election campaign staff were also recently arrested on charges of violating election laws.

His departure came about one week after the DP expelled another lawmaker, Rep. Kim Hong-gul, for failing to fully disclose his wealth during his mandatory property filing with the election watchdog in the run-up to the parliamentary elections in April. Kim was also under a party probe.

DP spokesman Rep. Huh Young expressed regret, saying the party will work to ensure the examples of Lee and Kim serve as a wake-up call to all of its members.

"We will firmly establish our party discipline to prevent the recurrence of such incidents, and redouble efforts for political reform," Huh said in a statement.

The latest departure brings the number of DP lawmakers to 174 in the 300-member Assembly. (Yonhap)