South Korea's ousted President Yoon Suk Yeol faces his final impeachment hearing Tuesday before judges decide whether to formally remove him from office following his controversial martial law declaration.

Yoon's suspension of civilian rule plunged the nation into political turmoil, leading to his removal by parliament in December. The 64-year-old has been incarcerated since his arrest last month on charges of insurrection, for which he could face a life sentence or even the death penalty. His trial began last week.

Tuesday's court session at Seoul's Constitutional Court marks Yoon's last chance to present his defense before eight judges deliberate behind closed doors to determine his fate. A verdict is expected in mid-March.

During the hearing, Yoon is expected to deliver a closing argument, with parliament's representatives presenting their case for his removal. Previous impeached presidents, Park Geun-hye and Roh Moo-hyun, waited 11 and 14 days, respectively, for their verdicts.

Should Yoon be removed from office, South Korea would be required to hold a fresh presidential election within 60 days.

The impeachment trial has largely focused on whether Yoon violated the constitution by declaring martial law, a measure reserved for national emergencies or times of war. Critics argue that Yoon’s actions were unjustified.

In his defense, Yoon's lawyer Kim Hong-il contended last week that "the declaration of martial law was not intended to paralyse the state" but to "alert the public to the national crisis caused by the legislative dictatorship of the dominant opposition party, which had crippled the administration."

Yoon’s legal team further argued that the martial law declaration was necessary to investigate claims of electoral fraud in last year’s parliamentary elections, claims that remain unsubstantiated.

Yoon's supporters, many of whom gathered in protest, have echoed the baseless claims of election fraud, with signs reading "Stop the Steal," a slogan popularized by former U.S. President Donald Trump after his 2020 defeat.

A survey by polling company Realmeter released Monday indicated 52 percent of South Koreans support Yoon's formal removal from office. However, a Gallup poll released last week showed 60 percent in favor and 34 percent against his impeachment.