Thailand's election commission says the leader of the Move Forward Party should be suspended as a lawmaker over a media shareholder issue. Pita Limjaroenrat is a candidate to become the country's next prime minister.

The commission has referred the case to the Constitutional Court. It alleges Pita held shares in a media company. It notes the country's constitution bans lawmakers from doing so.

The referral of the case comes a day before the parliament is scheduled to hold a vote to choose a new prime minister. Pita has the backing of eight allied parties. They are hoping to form the next government.

Meanwhile, incumbent Prime Minister Prayut Chan-o-cha announced on Tuesday he intends to retire from politics.

Prayut led a military coup in 2014. He was the army chief at the time. He later became the prime minister of the interim government.

Prayut has remained in power since he led the coup nine years ago.

He leads the United Thai Nation Party. But the party won only 36 of the 500 lower house seats in the May general election.

Prayut is expected to stay on as prime minister until a new government is formed.