There is no doubt that the nation needs a new Constitution that reflects the many changes of the past decades. The latest public opinion survey shows that nearly 80 percent of the general public and close to 90 percent of lawmakers support amending the basic law.

Most of all, the current Constitution, last revised in 1987 in the wake of a pro-democracy movement, is outdated in many aspects. The recent corruption scandal involving ousted President Park Geun-hye also bolstered the call for a new Constitution that gives less power to the chief executive.

It is against the backdrop that all major candidates in the May presidential election -- including President Moon Jae-in -- vowed to change the Constitution. Specifically, they agreed to hold a national referendum for a new supreme law on the next local election day in June next year.

The National Assembly launched an ad-hoc committee in January. What it has done so far, however, should raise concern about the goal of putting a new Constitution to referendum on the target day.

It was only last week that the committee set forth a specific timetable for the revision work. The panel plans to work out its own proposal for a new Constitution, submit it to the National Assembly in March and put it to a parliamentary vote by May 24, about 20 days before the June 13 election day.

One can easily see that is a tight time schedule. Few would agree that the panel comprising ruling and opposition parties could reach a consensus on every clause of the new Constitution in about four months from now.

The rival parties are already wide apart on some key elements of the new Constitution. Regarding the power structure, for example, President Moon’s ruling party wants to preserve the presidential system, changing the current five-year single term presidency to one that allows the president to serve up to two four-year terms. Opposition parties prefer a dual executive system and a parliamentary cabinet system.

Moon and other progressives also hope to include the past pro-democracy movements, including the 1980 Gwangju uprising and the 1987 popular protest, in the preamble to the new supreme law. Conservative parties and their supporters are staunchly opposed to the idea.

With the local election approaching fast, major parties will bear the poll in mind in dealing with the parliamentary business and other political issues. Then add the North Korea crisis to the national issues that could divert public and political attention away from the work to revise the Constitution.

Now Hong Joon-pyo, leader of the Liberty Korea Party, added himself to the already plentiful negative factors to the road to amending the Constitution, by calling for delaying it until after the local election. His logic is simple: Constitutional revision is a very important issue -- more important even than a single presidential election -- and it is inappropriate to hold a referendum simultaneously with the local election. He also argued that more time is needed to work out the best basic law for the nation.

For all the rhetoric, it is wrong for Hong -- who heads the largest conservative group that controls 107 parliamentary seats -- to try to run against what has become a solid public mandate. That he lost the election to Moon could not justify the reversal of a pledge he made as a candidate.

Moreover, voters are wiser than Hong thinks they are and able to make the right and fair judgement on what is a good Constitution and who are good candidates to represent their local communities at the same time.

Hong may believe that holding a referendum and local election on the same day may work to his party’s disadvantage as, for instance, a higher voter turnout usually benefits liberal candidates.

Any such short-sighted political calculation will only lower the chances of his party in the election and thereafter. As the leader of the second-largest parliamentary bloc, Hong ought to fulfill the public mandate to write a new Constitution.