A decision by Thailand's Constitutional Court to suspend Prime Minister Prayuth Chan-ocha from official duties on Wednesday was a blow to the former army chief who first came to power when he toppled an elected government in a 2014 coup.

The decision was a rare, though possibly brief, victory for opposition parties that have sought to loosen Prayuth's hold on power through elections, parliamentary manoeuvres and legal cases.

What led to the suspension?

The court suspended Prayuth while it considered a petition that he had reached an eight-year term limit set for prime ministers in the 2017 constitution written by a military-appointed committee after the coup and passed in a referendum.

The petition - by opposition parties that have failed to oust Prayuth in four no-confidence votes - says that because the army junta Prayuth led named him prime minister in August 2014, a few months after the coup, he reached the limit this week.

Wednesday's decision by the court was to accept and investigate that petition.

Some Prayuth supporters argue his premiership, in fact, started in 2017 when the new constitution came into force.

Others date Prayuth's term to 2019, when his pro-army party contested and won elections. Later that year, parliament elected him as civilian prime minister in a process opposition politicians have said was skewed to favour pro-army candidates. Prayuth's government says the elections were free and fair.

Who is in charge now?

Deputy Prime Minister Prawit Wongsuwan, 77, will be the interim leader after the court suspended Prayuth, government spokesman Anucha Burapachaisri told reporters.

Prawit, himself a former army chief, is a longtime royalist figure and considered a political kingmaker in the conservative movement.

If the court were to later rule that Prayuth had reached his term limit, the elected parliament would then pick a new prime minister from among qualified candidates who ran in the 2019 election.

Prayuth's Palang Pracharat party heads a 17-party coalition in parliament that should, combined with the votes of a military-selected senate, give it enough votes to decide the next prime minister.

What happens next?

The court has given Prayuth 15 days to respond to his suspension. But it did not set a timeline to issue a ruling on the petition itself.

Could Prayuth be restored?

Yes. If the court ruled that Prayuth's term officially began in 2017 or 2019, he could be reinstated.

That would mean he could stay in power until 2025 or 2027, depending on the results of the next elections.

Could there be elections soon?

The next elections are due by May next year under the constitution, but a sitting prime minister has the power to call early elections by dissolving the elected House of Representatives.

In that case, an election would be held within 60 days after a house dissolution.

However, ruling party members have said elections are unlikely until after Thailand hosts the Asia-Pacific Economic Cooperation leaders summit in November in Bangkok.

- Reuters