Thailand's prime minister has been removed by the Constitutional Court, plunging the country's politics into turmoil and dealing a blow to its most powerful political dynasty.

Paetongtarn Shinawatra was dismissed for violating ethics in a leaked June phone call, where she could be heard calling Cambodia's former leader Hun Sen "uncle" and criticising the Thai army, amid worsening border tensions with Cambodia.

The call, leaked by Hun Sen himself, damaged her reputation and critics accused her of undermining the country's army.

The ruling makes Paetongtarn, the daughter of former PM Thaksin Shinawatra, the fifth prime minister to be removed from office by the court since 2008.

On Friday, the court's nine judges voted six to three against Paetongtarn, ruling that her actions had violated ethical standards expected of her office.

The court said that Paetongtarn possessed a "personal relationship" that "appeared to align with Cambodia" and dismissed her claims that the call was a "personal negotiation to... bring back peace without using violence".

In a ruling, it said "caused the public to cast doubt" on whether her actions "would benefit Cambodia more than the nation's interest".

Paetongtarn acknowledged the court's verdict but insisted she was trying to save lives.

Her call with Hun Sen, at one time a close friend of her father, came as tensions rose on the Thai-Cambodia border, which weeks later erupted into a five-day conflict in which dozens of people were killed and hundreds of thousands fled their homes.

Paetongtarn, 39, had only joined Pheu Thai in 2021 and rose to power after her predecessor Srettha Thavisin was dismissed by the Constitutional Court for appointing an ally to his Cabinet who had been jailed for trying to bribe a judge.

Hours after she was dismissed, her one-time collation partner, the conservative Bhumjaithai party, announced it had enough support from other parties to get the votes needed to form a new government under leader Anutin Charnvirakul.

The party had earlier outlined its priorities, including resolving the border dispute with Cambodia and dissolving parliament within the next four months.

The powerful Shinawatra family have presided over several Thai governments - and Paetongtarn's removal is a blow to their political dynasty.

She becomes the third Shinawatra to have their premiership cut short: her father Thaksin was deposed by a military coup in 2006 and her aunt Yingluck was also removed by the Constitutional Court in 2014.

Despite his retirement from formal politics years ago, Thaksin remained hugely influential - though it's now unclear how much influence the Shinawatra name will now continue to bear.