The future of Thailand’s Prime Minister Srettha Thavisin as well as its leading opposition party looks set to be decided this week in four key court rulings that risk triggering a new political crisis.

The courts are due to announce rulings in four cases on Tuesday involving Srettha, former Prime Minister Thaksin Shinawatra, the leading opposition Move Forward Party (MFP), and the election process for a new Senate.

Thailand’s politics has been marred for years by a struggle between its military-backed conservative-royalist establishment, and populist and reform parties such as those backed by Thaksin and MFP, leading to mass protests and military coups.

“These cases highlight the fragility and complexity of Thailand’s political climate,” ANZ Research said in a note, warning of the potential for renewed protests.

What is the prime minister’s case?

Srettha, who made a fortune in property before getting into politics, became prime minister last August after Pita Limjaroenrat, who led MFP to victory in the May 2023 elections, was blocked from forming a government.

On Tuesday, he faces a decision – or potentially another hearing date – from the Constitutional Court on whether he breached the constitution by appointing someone to his cabinet who had a previous conviction.

Srettha, who denies any wrongdoing, could face dismissal if the court rules against him.

If he is removed, his Pheu Thai Party would need to propose a new candidate for prime minister and parliament would need to vote on their appointment.

What is the case against MFP?

A second case could lead to the dissolution of the reformist Move Forward Party (MFP), which won the most seats in last year’s election as well as the largest share of the vote.

The Constitutional Court is due to announce its decision – or another hearing – on an Election Commission complaint that alleges MFP broke the law by campaigning for reform of the royal insult law.

The party denies any wrongdoing.

It dropped its calls for reform after the Constitutional Court ruled in January that the call amounted to an effort to overthrow the monarchy.

Its predecessor, the Future Forward Party, was also dissolved by a court ruling after performing strongly in the 2019 election.

What about Thaksin?

Thaksin, the telecommunications tycoon who dominated Thai politics being removed in a military coup in 2006, returned to Thailand last year after Srettha’s government took office.

On Tuesday, a Bangkok criminal court is likely to formally charge him with royal insult in connection with a media interview he gave in 2015.

The court will then decide whether to grant bail to Thaksin, who has said he is innocent. “This case has no merit at all,” he told reporters earlier this month.

Thailand’s lese-majeste law, one of the world’s toughest, carries a maximum jail sentence of up to 15 years for each perceived insult.

The 74-year-old returned to Thailand to a rock star’s reception last August after 15 years of self-imposed exile.

And the senators?

The Constitutional Court will also deliver a decision on the ongoing selection of a new 200-member Senate, after accepting a petition questioning whether parts of the process, taking place over three successive weeks, were lawful.

If the process is cancelled or delayed, it would temporarily extend the term of military-appointed lawmakers who played a key role in forming the latest government, including last year’s manoeuvre that blocked MFP.

The current upper house was hand-picked by the military following a 2014 coup that removed an elected Pheu Thai government led by Thaksin’s sister, who still lives in self-imposed exile.

The extended process to pick the next Senate began on June 9.

Only candidates can vote in the process and they must all be over 40 years old with at least 10 years of experience in their field. Ten candidates will be chosen from each of 20 occupational groups with the results expected on July 2.