Thailand's Constitutional Court on Wednesday refused to hear a case on election winner Pita Limjaroenrat's thwarted bid to become prime minister, clearing the way for a new leadership vote in parliament.
The ruling means the new vote to choose a PM could come as early as Friday, potentially ending the deadlock that has gripped the kingdom since the general election in May.
"The Constitutional Court has agreed unanimously to not accept the case for a hearing," the court said in a statement.
Pita's Move Forward Party (MFP) won most seats in the May poll, riding a wave of support from young and urban Thais to end nearly a decade of army-backed rule.
But the Harvard-educated 42-year-old was defeated in his bid to become PM by a nexus of conservative forces spooked by his pledges to reform royal insult laws and business monopolies.
Pita dropped out of the running after parliament rejected him in a first prime ministerial vote and then denied him a second.
The case thrown out by the court on Wednesday had centred on the constitutionality of parliament refusing Pita a second vote.
The Pheu Thai party of exiled former premier Thaksin Shinawatra, which came second in the election, is now set to lead a multi-party coalition government without the participation of MFP.
Pheu Thai will nominate business tycoon Srettha Thavisin for prime minister, and the party says it is confident he will get enough votes to be approved.
To become prime minister, a candidate must be approved by a majority of both houses of parliament -- the 500 elected MPs and the 250 senators appointed under the last junta.
Pita could not muster enough support from senators, and several parties said they would play no part in any government that included MFP.
Last week the Bhumjaithai party -- which was part of the outgoing military-backed government -- joined Pheu Thai's new coalition.
Bhumjaithai, best known for delivering on a 2019 campaign promise to legalise cannabis in Thailand, had previously insisted it would not join a coalition containing MFP.
Pheu Thai is seen as a vehicle for the Shinawatra political clan, whose members include two former prime ministers ousted by military coups.
Thaksin, 74, has said he will return to Thailand in the coming weeks -- despite facing multiple criminal cases he says are politically motivated.
The policeman turned telecoms tycoon won two elections but was thrown out by the army in 2006 and has lived in self-exile for the last 15 years.
A bogeyman figure for Thailand's pro-military and royalist establishment, Thaksin still casts a long shadow over the kingdom's politics and his return has the potential to inflame an already-febrile atmosphere.