The row over the alleged meddling into the December presidential election by the National Intelligence Service is boiling over into a dispute over the legitimacy of the election.

Tossing fuel onto the raging controversy is Moon Jae-in, the presidential candidate of the main opposition Democratic Party. In a statement issued Wednesday, he declared that the December election was “unfair.”

He based his conclusion on the fresh allegations raised against the NIS, the military and the Ministry of Patriots and Veterans Affairs, as well as those that have already been made against the spy agency.

Claiming that what has been uncovered so far “is nothing more than the tip of the iceberg,” he slammed the government for attempting to stonewall the investigation into the allegations and mask the truth.

Moon argued “it is a brutal fact” that Park benefited from the illegal election campaigns by state agencies, whether she had any prior knowledge about their intervention or not.

In this regard, he called on Park to take responsibility for the irregularities and “the crisis of democracy” they have caused. Specifically, he demanded that “undue external pressure” on the prosecutors investigating the NIS scandal be stopped so that the truth could be brought to light.

He also urged her to reform the NIS and other state agencies and mete out stern punishments to those responsible to prevent a recurrence of the problem.

Moon’s statement is not a declaration of defiance. Although he openly cried foul more than 10 months after the election, he stopped short of calling for a re-run. Yet he did erode the legitimacy of the election by highlighting allegations of malpractice.

Moon also undermined Park’s legitimacy by saying that she definitely benefited from the illegal campaigns of state agencies. His statement insinuated that the election outcome could have been different had there been no illegal electioneering.

It is undeniable that state agencies posted messages against Moon on some Internet portal sites and Twitter in the run-up to the election. But it is difficult to say that Park benefited from such postings, given that there is no way to measure how many people voted for Park simply because of those messages.

Many DP lawmakers, including Moon, however, are convinced that the illegal online campaigns benefited Park. In particular, the new allegations of election meddling by the NIS and the Defense Ministry’s cyber warfare command led them to publicly question the legitimacy of the December election.

Yet DP leaders need to be cautious in calling into question the validity of the presidential poll as they could face backlash. It would be wise of them to wait for the court’s verdict on the allegations against the NIS and other agencies before jumping to a conclusion.

The ruling Saenuri Party vehemently attacked Moon and other DP leaders for attempting to defy the election result. But before bombarding them, Saenuri leaders need to heed the warning that the government and the ruling party will face bigger problems if they fail to address those exposed by prosecutors’ investigation.

In this regard, Park also needs to take action to dispel the allegations that the government has interfered with the NIS investigation. The best way to end the protracted dispute is to ensure that no stone is left unturned in investigating the spy agency and other state agencies.