Just two days after being disbanded by court order, Thailand’s main progressive political party has regrouped under a new name.

Leaders of the dissolved Move Forward Party announced they were forming a new party to be called the People’s – or Prachachon – Party.

They vowed to continue the fight for reforms despite continuing opposition from the conservative establishment that blocked the party from taking power despite finishing first in last year’s election.

Critics say the party’s dissolution was the latest attack on the country’s progressive movement in a long legal campaign by conservative forces.

On Wednesday, Thailand’s Constitutional Court unanimously ruled that the Move Forward Party violated the constitution by proposing to amend a law that criminalises insulting the royal family.

It also banned former Move Forward executives, including popular former chief Pita Limjaroenrat, from politics for 10 years.

Move Forward won the most seats in the 2023 general election, but conservative, military-appointed senators voted down its candidate for prime minister.

The party’s surprise victory was seen as reflecting widespread desire for democratic reforms, especially among younger voters, after years of military rule.

Legislators of a dissolved political party who are not banned from politics can keep their seats in Parliament if they join another party within 60 days.

Move Forward had 148 members of parliament, but five are now-banned executives who cannot continue to serve.

Speaking at the new party’s inaugural meeting, attended by the 143 remaining MPs and other party members, Parit Wacharasindhu announced that the reformed party would be named the People’s Party because it wants to be “a party from the people and for the people, and to work on creating a Thailand where absolute power belongs to the people”.

He named five new executive board members, including the new party’s leader, 37-year-old IT expert Natthaphong Ruengpanyawut.

Mr Natthaphong told the crowd the party would pursue the ambitious goal of winning enough seats to form a single-party government in the next elections in 2027.

Wednesday’s court ruling sparked international concern.

US state department spokesperson Matthew Miller said: “This decision disenfranchises the more than 14 million Thais who voted for the Move Forward Party in the May 2023 election and raises questions about their representation within Thailand’s electoral system.

“The Constitutional Court’s decision also jeopardizes Thailand’s democratic progress and runs counter to the aspirations of the Thai people for a strong, democratic future.

“The United States does not take a position in support of any political party, but as a close ally andfriend with deep and enduring ties, we urge Thailand to take actions to ensure fully inclusive political participation, and to protect democracy and the freedoms of association and expression.”

The European Union issued a similar statement. Volker Turk, the UN High Commissioner for Human Rights said the court’s ruling “was deeply troubling and undermines democratic processes and restricts political pluralism”.

He said: “This decision seriously impacts fundamental freedoms of expression and association, and people’s right to participate in public affairs and political life in Thailand.

“No party or politician should ever face such penalties for peacefully advocating legal reform, particularly in support of human rights.”

Prime Minister Srettha Thavisin told reporters on Thursday that he expects Move Forward to respect the court’s ruling and to find an appropriate way to continue its work.

When asked about the international reaction to the party’s dissolution, Mr Srettha said he understood that concerns were expressed in a spirit of goodwill, but “they don’t mean anything, because we have sovereignty and our own ways in terms of political and democratic developments”.