The parliamentary dismissal of the arrest motion for a ruling party lawmaker suspected of bribery is shameful for both of the major parties, which pledged to give up privileges given to legislative members.

The dismissal is expected to make voters more cynical and distrustful of the parties, especially the ruling Saenuri Party, whose members worry about its possible negative impact on the prospects of their candidate winning the presidential election in December.

Rep. Chung Doo-un, a three-term Saenuri lawmaker, survived Wednesday’s vote on the motion for his detention, while a similar one for independent legislator Park Joo-sun, formerly affiliated with the main opposition Democratic United Party, was passed. Chung was charged with receiving kickbacks from a savings bank owner in 2007 and Park was convicted of illegal electioneering during the April general elections.

Under the current law, the arrest of a lawmaker requires approval from a majority of National Assembly members while it is in session. The legislature has often come under fire for abusing the clause to protect its members from criminal punishment, earning itself the title of a “bullet-proof Assembly.”

The immunity from arrest was among the privileges granted to legislators that both the ruling and opposition parties pledged to abandon.

Though viewed by many observers as a ploy to win voters’ hearts in the lead-up to the presidential poll, such commitments have been seen as a positive movement toward overhauling the legislature.

The vote on the arrest motions for the two senior lawmakers drew keen attention as a litmus test of the parliamentary will to abide by the reform pledges.

Seemingly, the split results were more embarrassing to the Saenuri Party and provided the opposition with ammunition to attack the ruling party for reneging on their pledges.

Some Saenuri members appeared to have felt it would be unfair to treat Chung in the same way as Park, as their colleague faces a court hearing on the prosecution’s request for his detention while the independent lawmaker’s arrest was requested by a court that recently sentenced him to a prison term.

In the political context, however, this argument seems to make little difference as the Saenuri leadership had made it clear the party would ensure the outcome of the parliamentary vote and meet public expectations.

The dismissal of the arrest motion for Chung is also likely to do some damage to the campaign of the ruling party’s presidential frontrunner Rep. Park Geun-hye, who made public her second bid for the presidency a day before the vote.

The Saenuri floor leadership immediately offered to resign en masse to contain the fallout from their failure to pass the motion. This move, however, may still prove insufficient to get rid of the party’s image as being steeped in vested interests.

The DUP has tried to use the split results to differentiate itself from the ruling party. But a scrutiny into the vote counting shows at least 37 members of the party did not vote for Chung’s arrest, giving it little room to claim moral supremacy over the ruling party.

Some DUP lawmakers might have felt similarly to the Saenuri members sympathetic to Chung. But some critics suspect that they might have deliberately opposed Chung’s detention to direct the public ire toward the ruling party or to preempt the prosecution’s probe into allegations that DUP floor leader Park Jie-won also received money from the savings bank owner arrested for allegedly bribing Chung and Lee Sang-deuk, former lawmaker and elder brother of President Lee Myung-bak.

Though Park has vehemently denied the charges against himself, a decisive test for the parliamentary pledges toward self-reform could come if a request is made to approve the DUP whip’s detention.