efe-epaAlfredo Garcia Bangkok

Thailand's political landscape was gripped by uncertainty on Monday after King Maha Vajiralongkorn intervened in his elder sister princess Ubolratana Mahidol's bid to run for prime minister, leading the Election Commission to reject her candidacy.

The Commission said on Monday that it had accepted 45 prime ministerial candidates nominated by different parties, but had not yet decided whether to dissolve the party that nominated the King's sister.

Princess Ubolratana has been excluded from the list because "members of the royal family should hold themselves above politics", the Commission said in a statement. "They should remain politically neutral and should not hold any political office".

The statement followed a late night announcement by the King on Feb. 8, in which he called her bid to run in the elections on Mar. 24 "inappropriate", saying it would "defy the culture of the nation".

The Thai Raksa Chart party could also be dissolved or banned for filing the nomination of the princess as its sole candidate, as the election commission studies a petition that was filed on Monday to ban the party.

Meanwhile, a member of the Thai Raksa Chart retaliated with another petition to the Election Commission to reject the candidacy of current Prime Minister Prayut Chan-ocha, the head of the military junta who led a coup in 2014 to overthrow the democratically-elected government. His nomination was accepted by the Commission on Monday.

Princess Ubolratana's nomination on Friday as a candidate for prime minister caused a huge stir in Thailand, a country where the monarch is revered but whose members traditionally have stayed out of politics.

Hours after her nomination, the King released a televised statement on Friday night calling her candidacy "extremely inappropriate".

"A prominent member of the royal family becoming involved in politics, no matter how, goes against tradition," the King said.

The next day, the Thai Raksa Chart party announced that it would adhere to the royal order and withdrew Princess Ubolratana's nomination, leaving them without a prime ministerial candidate for the elections scheduled for next month.

Ubolratana's candidacy had initially been accepted by the Commission because she had formally relinquished her royal titles in 1972 following her marriage to an American, technically leaving her free to run in the election.

In a statement on Friday confirming her intention to run for prime minister, the princess said she wanted to exercise her rights and freedom as "a commoner".

The nomination of a former princess in a country where the monarchy is the most revered institution and where royal critics can face jail time of up to 15 years would have made it very difficult for any other candidates to oppose her.

The events of the last few days have generated such political uncertainty that social media in Thailand on Sunday were rife with rumors of an imminent coup after several tanks were reportedly seen in a province to the north of Bangkok, although military officials have said they were being moved amid preparations for the Asia-Pacific "Cobra Gold" defense exercises that are held annually in Thailand.

Rungrueng Pittayasiri, an executive member of the Thai Raksa Chart party, on Monday submitted his resignation to the Election Commission, claiming he had nothing to do with the nomination of the princess.

Thai Raksa Chart party is linked to former Prime Minister Thaksin Shinawatra, whose Puea Thai party has won every election that has been held since 2001. Shinawatra's sister Yingluck was prime minister when the government was overthrown in a coup in 2014.

Thaksin was also deposed in another coup in 2006 and has been living in exile since 2008.

The group loyal to Shinawatra is contesting the elections in through three different blocks - Puea Thai, Thai Raksa Chart and Puea Chart - because of an electoral law drafted by the military junta that bans large political parties.

The withdrawal of Ubolratana's candidacy would represented a major setback for the Shinawatras, who have been left without their star candidate, and if the Thai Raksa Chart party is dissolved, they would also lose many constituencies where only their candidates had filed nominations.