Partisan gridlock is expected to dominate the National Assembly in upcoming weeks, fueled by President Yoon Suk Yeol’s expected veto of a contentious bill that mandates a special counsel investigation into the death of a young Marine last year.

The main opposition Democratic Party of Korea, which railroaded the bill that was passed by the opposition-led Assembly on Thursday, is gearing up to respond to a presidential veto that is likely to be announced by July 19, according to its acting chair.

If the president does not veto the bill within 15 days after it is passed over to the Cabinet, the bill automatically becomes law. The special investigation bill was delivered to the Cabinet on Friday, a day after it was passed by the Assembly, setting a July 19 deadline.

The presidential office hinted Thursday that Yoon plans to veto the bill, which calls for the launch of a special counsel to investigate allegations that the Yoon administration and the military inappropriately interfered in an internal probe into the death of Cpl. Chae Su-geun, who died after being swept away by a torrent during a search and rescue mission in July last year.

The office immediately released a statement via a presidential official who declined to be named, calling the Assembly’s decision one of the most “embarrassing acts of legislative abuses in constitutional history.”

The Democratic Party is pushing for the revote of the bill to be held at the Assembly by the end of next week, under the likely scenario that Yoon exercises his veto power.

“We plan to push forward with the special investigation bill on the death of the Marine and uphold our earlier promise to pass the bill before the 1st anniversary of (Chae’s death on July 19),” main opposition acting chair and floor leader Rep. Park Chan-dae said Wednesday.

On Sunday, the Democratic Party called for Yoon to carry out his earlier pledge to “launch a special counsel investigation himself” if the progress of the ongoing investigations into the allegations of interference by the Corruption Investigation Office for High-ranking Officials and the police is lackluster.

The call points to a decision by an investigation panel of officials and experts at the Gyeongbuk Provincial Police, which is handling the case of Chae’s death, to exclude Lim Seong-geun, former commander of the 1st Division of the Marine Corps, to which Chae belonged, from the list of suspects to be referred to the prosecution. Lim was summoned and grilled by the police in May as an involuntary manslaughter suspect in connection with the death of Chae, who was his subordinate at the time of the incident.

Both the police and the CIO have been subjects of public criticism in recent months for their slower-than-expected investigations into Chae’s death and the officials’ interference in the internal probe, respectively.

On top of the Assembly's gridlock over the investigation bill, the rival parties are also projected to lock horns over rescheduling the date of the opening ceremony for the 22nd Assembly, whose term kicked off in late May. The ceremony, initially scheduled for July 5, was postponed indefinitely after the ruling People Power Party announced a boycott of the event and requested Yoon to do the same. It is customary for the president to give a keynote speech at the ceremony to mark the start of a new Assembly term.

The ruling party’s decision to boycott the ceremony came after the opposition-led Assembly passed the contentious bill on Thursday, with all but two ruling party lawmakers having participated in the vote, in a protest of the main opposition’s unilateral move. The People Power Party had staged a 24-hour filibuster ahead of the plenary session where the voting took place.