The launch of North Korea's long-range rocket is expected to become a big issue in South Korea's upcoming presidential election, political observers said Wednesday.

Observers said the surprise launch coming just seven days ahead of the Dec. 19 poll can raise uncertainty surrounding the Korean Peninsula and fuel concerns about national security.

Such developments can influence whom people will support when they go to cast their ballots, although its effects on public sentiments has yet to be determined.

"Experts are divided on the impact, with some predicting the launch will give credence to hardliners and help conservative presidential hopeful Park Geun-hye, while others said people may vote for Moon Jae-in of the liberal opposition party because they do not want an escalation of tensions," an election watcher said.

He added that because voters are already split between the conservative and liberal camps, the latest provocation by Pyongyang may not really affect the outcome of the race.

"The country as a whole has become 'indifferent' having already seen the North test numerous rockets and detonated two nuclear devices," the expert said. He added that because the launch had been expected people will be less likely to be moved.

In addition, both the ruling Saenuri Party and Democratic United Party (DUP) have all urged Pyongyang not to fire off the rocket for fear it can destabilize Northeast Asia and raise tensions between the reclusive communist countries and its neighbors.

Saenuri and the DUP, meanwhile, issued statements strongly condemning the North's latest actions.

The conservative party said the launch is a clear provocation by the North and violation of the standing United Nations resolution.

It called on the Seoul government to implement strong sanctions.

"The North must pay for its brash actions," the party said.

The DUP also said the launch violates international rules and will lead to further isolation of the country.

"The North must listen to concerns raised and not take any action that can endanger inter-Korean relations," said Rep. Woo Sang-ho, the head of the party's communications office.

The lawmaker, however, also blasted Seoul for failure to predict when the launch will take place. (Yonhap News)