By Joyce Lee SEOUL (Reuters) -South Korea's leadership crisis will play out in the Constitutional Court, which will decide the fates of President Yoon Suk Yeol and Prime Minister Han Duck-soo, both impeached and suspended from power over a short-lived martial law.

In a first for the country, a court issued an arrest warrant for a former president on charges of abuse of authority and orchestrating a rebellion.

The police are investigating whether President Yoon Suk Yeol tried to lead an insurrection when he declared martial law and plunged the country into crisis.

South Korea's acting President Choi Sang-mok said on Tuesday he would immediately move to fill vacancies on the Constitutional Court in a effort to restore stability after the impeachment of two of his predecessors this month triggered political turmoil.

The plane crash is the first major test for South Korea’s acting president, Choi Sang-mok, who was appointed the interim leader only on Friday, as the country grapples with a political crisis at the highest levels.

Finance Minister Choi Sang-mok became on Friday South Korea's second acting president in two weeks, as lawmakers voted to impeach the current acting leader, Prime Minister Han Duck-soo, fuelling political uncertainty in Asia's fourth-largest economy.

The lawyers for a former South Korean defence minister under investigation on insurrection charges said on Thursday a short-lived martial law decree imposed earlier this month was to raise alarm on opposition parties' abuse of the democratic process.