Paetongtarn Shinawatra, whose father and aunt have served as premier, would become the youngest leader in Thailand's history as a constitutional monarchy if elected.

She would also become the kingdom's second woman prime minister, after her aunt.

The vote, slated to begin at 10 am (0300 GMT), was forced after the kingdom's top court sacked premier Srettha Thavisin for appointing a cabinet minister with a criminal conviction.

Srettha's ouster on Wednesday was the latest round in a long-running battle between the military, pro-royalist establishment and populist parties linked to Paetongtarn's father, a telecoms tycoon and one-time Manchester City owner.

The Pheu Thai party selected Paetongtarn as its replacement candidate Thursday. None of the 10 other parties in the coalition it leads put forward an alternative.

Bhumjaithai -- the third-largest party in parliament -- said it had "agreed to support a candidate" from Pheu Thai in Friday's vote.

Paetongtarn must now secure 247 ballots from the body's 493 sitting members. 

"We are confident that the party and coalition parties will lead our country," she said after the party announced her candidacy.

However, in Thailand's tumultuous brand of politics, a win in parliament is not assured.

Paetongtarn, who has never held elected office, helped run the hotel arm of the family's business empire before entering politics three years ago and was a near-constant presence on the campaign trail in 2023.

That year's national election saw the fledgling Move Forward Party top the vote-getting after pledging to reform the country's strict lese-majeste laws and break up powerful business monopolies.

But alarmed senators blocked MFP's attempt to form a government.

Pheu Thai subsequently formed an alliance with pro-military parties once staunchly opposed to Thaksin and his followers, leading to Srettha's ascension.

Less than a year later, he became the third Pheu Thai prime minister to be kicked out by the Constitutional Court.

Srettha was ousted over his appointment of Pichit Chuenban, a former lawyer associated with Thaksin's family who had a criminal conviction.

Last week, the court also voted to dissolve MFP and ban its executive board members from politics for 10 years.

Thaksin Shinawatra has cast a remarkable shadow over the kingdom's politics for two decades.

He transformed Thai politics in the early 2000s with populist policies that won him and his party enduring loyalty from the rural masses -- and two elections.

But that success came at a cost: he was despised by Thailand's powerful elites and conservative establishment, who saw his rule as corrupt, authoritarian and socially destabilising.

Ousted as prime minister by the army in 2006, Thaksin took himself into exile two years later but never stopped commenting on national affairs -- or meddling in them, according to his critics.

Thaksin returned to the country last year.

Paetongtarn, known in Thailand by her nickname Ung Ing, is Thaksin's youngest child.

She grew up in Bangkok and studied hotel management in Britain, then married a commercial pilot. The couple now have two children.

Paetongtarn shares her jet-setting lifestyle with almost a million followers on Instagram.