Bangkok: Thailand's electoral commission on Tuesday said it will ask the Constitutional Court to dissolve the reformist Move Forward party (MFP).
The MFP won the most seats in last year's general election.
The commission said that it had agreed "unanimously" to seek the dissolution of the party.
In its campaign, the MFP had promised to reform kingdom's laws against insulting the Thai monarchy.
"There is evidence that Move Forward undermines the democratic system with the king as the head of state," the commission said.
"The Election Commission has considered and analysed the Constitutional Court verdict and has decided unanimously to ask the Constitutional Court to dissolve the Move Forward party."
MFP had proposed amending article 122 of Thailand's criminal code, which carries an up to 15 years prison sentence for insulting the royal family.
The monarchy is enshrined in the kingdom's constitution to be held in a position of "revered worship."
Earlier this year, the Constitutional Court ruled that the pledge to reform the legislation amounted to an attempt to overthrow the monarchy.
Reform of lese majeste laws was a major demand of mass demonstrations in 2020. Hundreds of people have faced charges over allegedly insulting the royal family during and in the wake of the protests, according to legal group Thai Lawyers for Human Rights.
The MFP scored the most votes in May elections after promising to reform the military, break business monopolies and reform royal insult laws.
After the election success, the party's leader at the time, Pita Limjaroenrat, was blocked from becoming prime minister by conservative factions in the Senate which argued the MFP posed a threat to the monarchy.
In January, the Constitutional Court cleared him of breaching election laws in a separate case.
The MFP's predecessor, Future Forward, was disbanded by the Constitutional Court in 2020 for violating campaign funding rules.