Ruling and opposition party leaders are going all out to win the hearts and minds of voters during the weekend ahead of this week's parliamentary election, political watchers said Sunday.

Up for grabs are the 300 seats in the unicameral National Assembly that will be decided on Wednesday. The lawmakers elected will hold office for four years.

"With so many districts too close to call at present, party leaders are doing their best to boost chances for their candidates," a political watcher said.

He said in Seoul alone, around 20 out of 49 seats are difficult to predict, especially with so many voters saying they have yet to decide.

Reflecting the critical nature of the race to win as many seats as possible in Seoul, leaders of the ruling Saenuri Party, the main opposition Minjoo Party of Korea and the splinter People's Party all converged on the capital city.

Saenuri chief Kim Moo-sung visited 11 districts in Seoul on Sunday to rally support for the party's candidates. He focused on visiting tightly contested regions.

The lawmaker, who left his own constituency in Busan to the care of his wife, emphasized that the opposition has made it a habit of opposing everything the Park Geun-hye administration tried to push forward.

"The opposition thinks that only by causing the incumbent administration to fail can they win power," he said.

Kim is then expected to travel to the industrial city of Ulsan,

414 kilometers southeast of Seoul, later in the day to help bolster chances of Saenuri party candidates there.

Kim Chong-in, the Minjoo Party's interim chairman, visited six districts in Seoul, then toured several constituencies in nearby Gyeonggi Province.

The party leader is expected to wrap up the day's campaign back in the capital city where he is expected to ask people for support.

In a rally in Seoul, he said people must now decide whether they will pick Saenuri or the Minjoo Party, stressing a vote for the later will bring about change.

His calls are aimed at preventing the split up of opposition-leaning votes from going to the People's Party led by Rep. Ahn Cheol-soo that could result in an easy victory for Saenuri.

Ahn, meanwhile, whose popularity has risen in the Jeolla region of the country, supported rallies of four candidates in Seoul. The party's co-chairman, Rep. Chun Jung-bae, who has generally stayed in Gwangju, will join Ahn in street rallies in the capital city to fuel support for the minor party. (Yonhap)