People participate in a rally calling for President Yoon Suk Yeol's impeachment in Jongno District, Seoul, Saturday. Yonhap

As President Yoon Suk Yeol awaits the Constitutional Court's ruling on his impeachment, nearly 70 percent of Koreans believe the court should uphold the impeachment, citing his declaration of martial law as valid grounds for removal, a poll showed on Tuesday.

The poll shows that the majority of the public does not agree with his account that martial law was an act of governance inevitable to quell "anti-state forces" and maintain public order.

According to the public opinion poll conducted by Hankook Research at the request of The Korea Times, 69 percent of 1,000 adult respondents said that the court should uphold the impeachment motion passed at the National Assembly so he could be removed from office. Another 28 percent said the motion should be dismissed to allow Yoon to return to office.

By age group, support for the conservative president's impeachment was the highest among those aged 40 to 49 (90 percent), followed by those in their 20s (82 percent), 30s (77 percent) and 50s (70 percent).

Older age groups, traditionally more right-leaning, showed more support for the court to dismiss Yoon's impeachment motion, with 56 percent of respondents in their 70s and 45 percent of those in their 60s saying so.

Broken down to political leanings, among self-identified liberals, 93 percent supported Yoon's impeachment, while 34 percent of conservatives backed it. The poll also revealed that the conservative president lost popularity among moderates as well, with 78 percent of those identifying themselves as centrists expressing support for upholding his impeachment.

The National Assembly passed the impeachment motion against Yoon on Dec. 14 over his botched martial law declaration on Dec. 3, which lasted only six hours. During the emergency military rule, hundreds of armed troops and police officers were dispatched to the Assembly, blocking lawmakers from entering the compound.

Dozens of military officers, including those from the intelligence unit, were deployed to the National Election Commission headquarters and its two other branches, in what Yoon later described as "an attempt to look into election fraud allegations."

Opposition parties have criticized Yoon's declaration of martial law as a violation of the Constitution and relevant laws, arguing that these actions constituted an insurrection. But the president defended his actions as a lawful exercise of presidential power aimed at "defending the nation's free democracy."

Yet Yoon appears to have failed to convince the majority of the public, according to the poll, which showed that 71 percent of respondents agreed that the martial law declaration constituted treason and, thus Yoon deserves impeachment, while 29 percent disagreed.

Support for the notion that the imposition of martial law was treasonous was overwhelmingly high among supporters of opposition parties, with 98 percent of main opposition Democratic Party of Korea supporters and 95 percent of minor Rebuilding Korea Party supporters in favor.

In contrast, 81 percent of supporters of the conservative ruling People Power Party (PPP) believed the martial law declaration did not constitute treason. This aligns with the party's move to defend the president from impeachment.

A majority of the 108 PPP lawmakers boycotted the first voting on Yoon's impeachment motion on Dec. 7, with only three of its members casting ballots in the anonymous voting. The PPP members participated in the second vote on Dec. 14, but ultimately failed to prevent the impeachment, as the motion was passed with 204 in favor and 85 against.

The Korea Times commissioned the survey to gauge public sentiment. Hankook Research surveyed 1,000 adults in phone interviews on Thursday and Friday. The poll has a margin of error of plus or minus 3.1 percentage points, with a credibility rate of 95 percent. Further details are available on the National Election Survey Deliberation Commission's website.