The parliamentary speaker called Tuesday for an end to a group of privileges granted to lawmakers, saying the National Assembly should win back public trust after last week's widely condemned rejection of an arrest motion for a fellow lawmaker.

"Now the National Assembly should indeed lay down their outdated privileges," parliamentary speaker Kang Chang-hee said in a speech in the National Assembly marking the 64th Constitution Day.

The comment came amid criticism of the parliament's rejection of a motion to arrest Chung Doo-un, a ruling Saenuri Party lawmaker suspected of bribery.

The National Assembly's veto called into question the ruling party's recent commitment to give up privileges granted to lawmakers, including immunity from arrest.

South Korea introduced immunity from arrest to protect opposition lawmakers from military-backed governments in the past, but the privilege often came under public fire as some legislators abused the clause to make unfounded allegations or to evade arrest.

Parliamentary consent is needed to arrest a lawmaker while the parliament is in session.

Kang also called on lawmakers to cooperate to realize economic democracy in a country where critics say family-controlled conglomerates, known as chaebol, wield significant clout often at the expense of small- and medium-sized companies.

Chaebol have played a key role in boosting South Korea's export-driven economy in recent decades, though they have long been a target of public criticism over their perceived abuse of economic power.

Kang said economic democracy would help resolve the social polarization that has gripped the Asia's fourth-largest economy in recent years.

The gap between workers in the highest and lowest wage brackets hit its widest margin ever last year, according to a labor research institute.

Last year, the country's highest wage bracket representing the top 20 percent of wage earners took home 5.4 times the salary received by the lowest bracket of the bottom 10 percent, the Korea Labor Institute said in January. (Yonhap News)