Presidential candidates from the ruling party and the main opposition on Monday criticized a panel's decision to ban articles by Yonhap News Agency on mainstream internet portals.

A committee jointly formed by leading web portals -- Naver and Daum -- in 2015 to evaluate news partnerships on Friday announced that the two portal operators should cancel their partnerships with Yonhap, in a measure that limits readers from viewing the agency's news articles on the portal sites for one year, as the country's leading news agency failed to meet a set of criteria to keep its articles appear in real time newsstands and mobile phones.

Yonhap new articles were suspended from appearing on Naver and Daum starting on Sept. 8 for over a month for having published advertorials. The ban was the longest the committee has imposed on a partner news outlet.

In a Facebook post, Lee Jae-myung of the ruling Democratic Party called on the committee to withdraw the "excessive and unfair double penalty," saying that the decision could be seen as a move to limit freedom of the press.

"As the country's representative news agency and picked as the most trusted news outlet by South Korean journalists in August, I am worried that the 'unlevel playing field' could worsen if (Yonhap) disappears from the portals during an important time in the presidential race," he said.

The chief spokesperson of Yoon Seok-youl, the presidential nominee of the main opposition People Power Party (PPP) criticized the one-year suspension as an "excessive" measure when compared to the agency's level of fault and urged the committee to reconsider its decision.

"Yonhap News Agency has made various efforts to responsibly correct its mistake but the news partnership evaluation committee has ignored them and made the excessive decision to kick it out from the portal sites," Rep. Lee Yang-soo, Yoon's chief spokesperson, said.

He added that the decision can "seriously limit" Yonhap's function as a representative news agency that has worked to defend "information sovereignty" and the public's right to know. (Yonhap)