BANGKOK: Thailand's main opposition leader on Wednesday accused judges of mounting a "judicial coup", after court rulings that ousted the kingdom's prime minister and dissolved its most popular party.

The Constitutional Court earlier this month disbanded the progressive Move Forward Party (MFP) and banned its leaders from politics, before throwing then-premier Srettha Thavisin out of office for ethics violations.

MFP, which won most seats in last year's election, swiftly relaunched as the People's Party (PP), and its new leader Natthaphong Ruengpanyawut told AFP that reform was needed for the kingdom to progress.

"The Constitutional Court has ousted the PM, and also ousted the ex-executives of MFP - we call it a judicial coup," he said in an interview at the Thai parliament.

"A power that is not accountable to the people overruled the executive branch and legislative branch which are elected by the people. This is a sign that Thailand is not a full democracy," he added.

Natthaphong, a 37-year-old tech entrepreneur, said his party will push for reforms to limit the Constitutional Court's powers to vet legislation - removing its ability to dissolve political parties or sack prime ministers.

Thailand's politics over the past two decades has been scarred by a bitter struggle between populist progressive parties and the kingdom's pro-military, pro-royalist elite.

MFP's popular leader Pita Limjaroenrat led the party to a surprise first place in last year's election promising to reform Thailand's tough lese-majeste laws, reduce military influence and tackle powerful business monopolies.

But he was blocked from forming a government by senators appointed by the last military junta, ostensibly because of concerns about the party's plans for the royal insult laws.

A court later ruled that the proposals amounted to an attempt to overthrow the constitutional monarchy, and on August 7, MFP became the latest in a series of Thai political parties to be dissolved by judges.

The European Union, United States, United Nations and human rights groups blasted the court's dissolution of MFP, with the EU saying it harmed democratic openness in Thailand.

Natthaphong urged the international community not to stint in its criticism when Thailand breached democratic norms, saying the kingdom "deserves to know when it's doing wrong".

Natthaphong said the new party would talk to conservative groups and courts to try to convince them about its plans for reform.

But he insisted PP would not back down on the substance, even on the sensitive subject of royal defamation laws - known in Thailand as 112 from the relevant section of the criminal code.

"The only thing we are going to change is the methodology or the approach," he said.

"We are not going to change the principle. The principle is... to accept that the 112 law has a problem."

Thailand has some of the world's strictest lese-majeste laws shielding King Maha Vajiralongkorn from criticism, and human rights groups say they have been abused in recent years to stifle legitimate debate.

PP is targeting a clear majority in the next general election, due in mid-2027, but there are inevitably fears that the party will suffer more judicial intervention or be blocked from taking office again.

In either event, Natthaphong said the party would not encourage its supporters to take to the streets for the kind of mass protests seen repeatedly in Thailand in the last 20 years.

"I think that the only reason our MPs or the PP would engage with street protests would be if Thailand has its next coup d'etat," he said.

"We are going to move on from street protests because we are not going to give a reason to the army to do a coup d'etat."

 - AFP