Thailand's Constitutional Court dismissed Prime Minister Paetongtarn Shinawatra from office on Friday for an ethics violation after only a year in power, dealing another crushing blow to the Shinawatra political dynasty that could usher in a new period of turmoil.

Paetongtarn, who was Thailand's youngest prime minister, becomes the sixth premier from or backed by the billionaire Shinawatra family to be removed by the military or judiciary in a tumultuous two-decade battle for power between the country's warring elites.

In its verdict, the court said Paetongtarn violated ethics in a leaked June telephone call, during which she appeared to kowtow to Cambodia's former leader Hun Sen when both countries were at the brink of an armed border conflict.

Fighting erupted weeks later and lasted five days. The decision paves the way for the election by parliament of a new prime minister, a process that could be drawn out, with Paetongtarn's ruling Pheu Thai party losing bargaining power and facing a challenge to shore up a fragile alliance with a razor-thin majority.

In a 6-3 decision, the court said Paetongtarn had put her private interests before those of the nation and damaged the reputation of the country, causing a loss of public confidence.

"Due to a personal relationship that appeared aligned with Cambodia, the respondent was consistently willing to comply with or act in accordance with the wishes of the Cambodian side," the court said in a statement.

The ruling brings a premature end to the premiership of the daughter and protégé of influential tycoon Thaksin Shinawatra. Paetongtarn, 39, was a political neophyte when she was thrust abruptly into the spotlight after the surprise dismissal of predecessor Srettha Thavisin by the same court a year ago.

'Tried to safeguard country's interests'

Paetongtarn has apologised over the leaked call and said she was trying to avert a war.

Paetongtarn said on Friday she had sought to safeguard the country's interests in a phone conversation with Cambodia's former leader that led to her dismissal by the Constitutional Court.

"The verdict today caused a change in Thai politics, we all have to help, all sides, whether government or opposition, or the people, all of us have to work together to build political stability and to ensure that there won't be another turning point again," she told reporters.

What happens next?

Deputy premier Phumtham Wechayachai and the current cabinet will oversee the government in a caretaker capacity until a new prime minister is chosen by parliament, on a date to be decided by the house speaker. The constitution does not specify a time-frame for when the lower house must convene. The court ruling opens the door to a flurry of dealmaking and horse-trading between parties and other power-brokers, with the central figure almost certain to be Paetongtarn's influential father and former premier, Thaksin Shinawatra, 76, the billionaire founder of her Pheu Thai party. With many competing interests, the process could take time.

The stakes are high, with the ruling coalition holding a razor-thin majority of just seven seats, meaning any shifts in allegiance away from the alliance could be costly for Pheu Thai and the Shinawatra political dynasty.

Who are the PM candidates?

There are five remaining eligible candidates from those declared prior to the 2023 election. Pheu Thai had three initially, but is now left with only one, Chaikasem Nitisiri, 77, a former justice minister and attorney general who has kept a low profile, but has said he is ready to step up.

Another possibility is Anutin Charnvirakul, 58, an ambitious former interior minister and deputy premier whose Bhumjaithai party quit Paetongtarn's coalition in June.

Also eligible are current Energy Minister Pirapan Salirathavibhaga, former deputy prime minister Jurin Laksanawisit, and ex-premier Prayuth Chan-ocha, a general who led a 2014 coup against the last Pheu Thai government. Prayuth, 71, is retired from politics and is currently a royal adviser.

Bhumjaithai party to hold talks with main Opposition

The leaders of Thailand's Bhumjaithai party will hold talks with the opposition People's Party, the largest force in parliament, an official said on Friday, after a court's dismissal of Paetongtarn Shinawatra as premier for an ethics violation.

Bhumjaithai's leader Anutin Charnvirakul is among five candidates eligible to become prime minister. The Bhumjaithai party in June quit Paetongtarn's coalition, in which it was the second-largest party.