In the first weeks of each year, political parties are busy mapping out plans and schedules for the New Year. This year, one of their major concerns will be preparing for the general elections in April 2020, the first parliamentary elections since President Moon Jae-in took power.

In relation to this, the parties’ most urgent job should be reaching an agreement on electoral reform. Also important is to work out a bipartisan bill to revise the Constitution.

It was fortunate that the five parties in the Assembly -- which had fought a war late last year that pitted the two largest parties on one hand against three smaller parties on the other -- managed to agree that they work out an accord on electoral reform by the end of this month.

The escalating tension between Cheong Wa Dae and the main opposition Liberty Korea Party over a whistleblowing scandal about the presidential office’s alleged interference with surveillance on civilians and appointment of public enterprise executives should not affect the parties’ agreement on electoral reform.

Most of all, a new electoral system that will set the number of lawmakers to be elected in the 2020 election and draw up new electoral maps should be in place at least one year before the polling date. Considering the time needed to get new bills through the National Assembly, a bipartisan agreement must come within this month.

Changing the current electoral system is necessary because it does not fairly reflect the voters’ preferences. Currently, the National Assembly has 300 members, 253 of whom are elected from single-seat constituencies and 47 by proportional representation. Voters cast two ballots – one for candidate and the other for the party of their choice for the proportional representatives.

Problems stem from the system in which only one lawmaker is elected in each constituency -- which makes ballots cast for all the other candidates “dead votes.”

As a result, there is a gap between the proportion of votes a party gets and its actual number of seats. Take the 2016 elections as an example. The Democratic Party of Korea won 110 constituencies with 37 percent of the total votes, while the predecessor of the Liberty Korea Party won 105 constituencies with 41.5 percent of the votes.

Minor parties face a bigger disadvantage. The predecessor of the Bareunmirae Party and Party for Democracy and Peace won a total of 38 seats, or 12.7 percent of the total parliamentary seats, whereas they garnered a combined total of 26.7 percent of the votes. It would be strange if the minor parties were not desperate to change the system. It was against this backdrop that the leaders of two minor parties went on a hunger strike last month to get a concession from the Democratic Party and the Liberty Korea Party.

Another big problem with the current single-seat-constituency system is the perpetuation of regionalism, as a conservative party based in the southeastern region – the current Liberty Korea Party -- and a liberal party supported by voters in the southwestern region – the current Democratic Party – dominate their own home turfs.

What should be the core reform of the current system is evident. The number of seats for proportional representatives should be increased and it should be determined in proportion to the total number of votes a party’s candidates win. That could enhance fairness and foster a multiparty system, which has so far eluded Korean politics.

In relation, the 2015 proposal made by the National Election Commission could be a good model. It suggested that 200 lawmakers be elected in constituencies and 100 chosen under the new proportional representations system.

Another positive aspect of such an electoral reform is that it will facilitate a wider political reform – including the change of the power structure and other key elements of the Constitution which is a product of the 1987 pro-democracy movement.

Overhaul of the 1987 supreme law whose focus was on ending a successive military rule is already overdue, and President Moon Jae-in, National Assembly Speaker Moon Hee-sang and other political leaders should take the lead in getting the country a new basic law that fits it. Real political reform cannot be accomplished without a constitutional revision.