The main opposition Democratic United Party is seeking to protect its embattled floor leader, Rep. Park Jie-won, no matter what. Park is facing an investigation over allegations that he received more than 100 million won in bribes from two distressed savings banks.

To protect Park, a top-notch election strategist, the party is even moving to use the widely criticized practice of creating a “bullet-proof” Assembly ― prolonging Assembly sessions simply to prevent prosecutors from arresting lawmakers.

Mindful of public criticism, Rep. Lee Hae-chan, the party’s chairman, stopped short of expressly saying so, but he clearly had this option in mind when he said Tuesday that the DUP would convene another extraordinary parliamentary session from Aug. 4 right after the current one ends on Aug. 3.

He asserted a successive session was necessary because the ongoing one failed to deal with many important matters, such as reviewing the government’s budget settlement reports and launching a parliamentary probe into the illegal surveillance of civilians by the Prime Minister’s Office.

The issues cited by Lee, however, cannot be seen as a valid reason for holding a new session without a break because they are either not so urgent or can be addressed during the remainder of the ongoing session.

Lee’s assertion exposed his thinly veiled intention to make the National Assembly a sanctuary so that the party’s floor leader could stay beyond the reach of prosecutors.

Under the current law, prosecutors cannot detain or arrest a lawmaker for questioning when the National Assembly is in session. To arrest a lawmaker during a session, they need to obtain parliamentary approval. Yet lawmakers tend to show strong solidarity when they vote on arrest motions on their peers, regardless of their party affiliations.

This was demonstrated earlier this month when Saenuri and DUP legislators collaborated to vote down an arrest motion on Rep. Chung Doo-un of the ruling party. Chung was also suspected of having received bribes from savings banks.

The vote outcome was all the more dismaying because it followed a public pledge of the lawmakers from the two parties to give up their immunity of arrest as part of their bid to reform the legislature.

Lee’s plan to hold a new session in August implies that he believes lawmakers would not vote for an arrest motion on Park. In fact, Saenuri legislators may find it difficult to vote for the arrest of the DUP floor leader as they have opposed the arrest of their own party member.

If Lee is right, the DUP would be able to safeguard Park against prosecutors’ arrest attempt if it keeps the parliament open in August. Come September, the Assembly will go into a 100-day regular session, which will continue until the presidential election in December.

Against this backdrop, prosecutors again asked Park on Wednesday to voluntarily appear at the Supreme Prosecutors’ Office today for questioning. It was their third summons following the previous two sent on July 19 and 23. But the lawmaker said he would reject it, as he had already done twice.

Now prosecutors are expected to request an arrest motion for him, hoping for Saenuri lawmakers’ full support. The National Assembly is expected to convene a plenary session on Aug. 2 to vote on the motion.

The current situation must be frustrating and humiliating for prosecutors. But they need to realize that the outright defiance by Park and the DUP of their investigative authority stems from their failure to enforce the law in a fair and just manner.

In this regard, the resistance of Park and his party to prosecutors’ investigation is understandable to some degree. But that isn’t to say that their behavior is justifiable.

Park argued his innocence by saying that he would commit hara-kiri at the train station in Mokpo, his constituency in South Jeolla Province, if he were found to have received illicit money from the two savings banks ― Solomon and Bohae.

But his claim of innocence is not convincing because if he is really innocent, there is little reason for him to refuse so adamantly to comply with prosecutors’ summons.

This view has been expressed by some of the eight DUP presidential hopefuls. They rightly noted that even if the party might be able to protect Park, allegations of corruption against him would not go away, weighing on the party’s campaign for the presidential election.

The party will also have to face outrage for using the National Assembly to shield its floor leader.