The upcoming leadership election of the main opposition Democratic Unified Party is to be the largest ever.

In the citizen voter registration that ended Saturday, 643,353 voters registered, according to party officials.

Together with 127,920 party members, the registered voters are to select a six-member decision-making body, and the lawmaker who receives the most votes will be named chairperson.

The results of the mobile vote will be combined with the party delegates’ vote, which will take place during the party’s national convention this Sunday.

“Due to the large number and wide range of voters, there is little room for candidates and party powers to influence the turnout,” said the party’s spokesperson.

“It has also become difficult to predict the final results.”

The party recently narrowed down the number of candidates who will vie for its chairmanship to nine.

The list includes former Prime Minister Han Myeong-sook, former Democratic Party floor leader Park Jie-won, former policy committee chairwoman Park Young-sun and civic group-based candidate Moon Sung-keun.

The corresponding race is in the public spotlight as it is the first official one since the former main opposition Democratic Party bonded with the civic group-based Citizen Integration Party.

Also, the elected chairperson and council are to lead the newly formed party after the general election in April and possibly the presidential election in December as well.

By Bae Hyun-jung (tellme@heraldcorp.com)