The meeting between President Moon Jae-in and presidential nominee Lee Jae-myung of the ruling Democratic Party was probably inevitable.

Quite a number of party members still have bitter feelings toward him in the aftermath of the race to select a presidential candidate, and Lee may have felt the urgent need to create a united front. He wasted no time, visiting Cheong Wa Dae about an hour after registering with the National Election Commission as a preliminary presidential candidate.

Of course, there is no reason for the incumbent president -- who is a registered member of the ruling party -- not to meet the party’s presidential nominee.

There are precedents of sitting presidents meeting with presidential candidates from government-affiliated parties before elections. Cheong Wa Dae cited the 2012 meeting between former Presidents Lee Myung-bak and Park Geun-hye when Park was the conservative Saenuri Party’s candidate.

But it is questionable if the timing of the Moon-Lee meeting was appropriate. Park was not the subject of a criminal investigation in 2012. None of the presidential candidates who had previously met with presidents before elections were under suspicion in corruption cases.

On the other hand, Lee’s close associates are under investigation by the prosecution in connection with the Daejang-dong land development scandal. His meeting with Moon took place at a sensitive time, when it could not but invite political controversy.

Cheong Wa Dae and the Democratic Party warned the public not to read too much significance into the meeting, beyond an occasion to celebrate Lee’s presidential candidacy win, but concerns about Moon’s duty to stay neutral in elections will not vanish easily. In South Korea’s electoral system, the incumbent president is required to remain neutral in any election, particularly one so close at hand.

Moon recently suspended all Cheong Wa Dae meetings with government officials and ruling party lawmakers as a show of his neutrality, but he is still under a cloud of suspicion in that the interior and justice ministers he appointed to handle issues related to candidates and elections are ruling party lawmakers. His meeting with Lee only fanned that suspicion.

Cheong Wa Dae emphasizes that it was an informal meeting behind closed doors and there was no dialogue that could have caused political misunderstanding. However, not many people would take this explanation at face value.

An official meeting between the president and the ruling party’s presidential nominee, so soon before an election, carries a strong symbolic meaning in itself. Speculation is inevitable.

Even though Cheong Wa Dae says Moon and Lee did not even utter the word “Daejang-dong,” their meeting effectively puts tacit pressure on the prosecution as it investigates the scandal.

Besides, it is hard to dismiss the view that Moon effectively certified Lee as his preferred successor. It is also questionable whether they made a deal, such as Moon protecting Lee from the Daejang-dong scandal in return for Lee guaranteeing protection for Moon from potential litigation after his retirement.

Their meeting came 14 days after Moon instructed the swift and thorough investigation of the scandal. Lee was mayor of Seongnam, Gyeonggi Province, when the project to develop the city’s Daejang-dong area was executed. Suspicions are piling up around Lee.

As a matter of fact, the prosecution is being denounced for its passive approach to the investigations. The current situation necessitates the appointment of a special counsel. By meeting with Lee while looking away from the problem, Moon has fed doubt about his willingness to maintain neutrality in elections.

This is not the first time Moon’s neutrality has been disputed. In February, ahead of mayoral elections in Seoul and Busan, Moon visited Gadeokdo, an island in Busan mentioned as one possible location for a new airport, in an apparent move to boost the ruling party candidate’s campaign.

One of the most important tasks ahead for the president in the closing days of his presidency is to maintain political neutrality and ensure a fair election. Moon must declare his commitment to stay election neutral and carry out that commitment faithfully.