The Future Forward Party (FFP) filed two libel suits Wednesday against a minor royal and TNEWS news agency, over claims the party is trying to supplant the monarchy.
In one suit, the FFP, led by party leader Thanathorn Juangroongruangkit, accused Mom Chao Chulcherm Yugala of defaming the party by posing misleading content in a Facebook post.
In his post, MC Chulcherm said the FFP's policy was subversive to the monarchy.
MC Chulcherm is a descendant of Prince Yugala Dighambara, one of King Rama V's sons.
In another lawsuit, the party accused Ekkachai Ruangchai, 26, the news editor of TNEWS, of defaming the party by summarising part of MC Chulcherm's comment and publishing it.
FFP spokeswoman Pannika Wanich said it is the first time the party has pursued a libel case against the press. "The media has lambasted our party for the past 10 months but we never pursued legal action because we believe in freedom to criticise," she said.
But TNEWS "really deserved this lesson" because it has a record of committing serious violations of media ethics, Ms Pannika said.
She said the party decided to use the libel law instead of the computer crime law because it opposes the use of the latter to silence critics.
She assured all other media outlets that they could criticise the party "as usual", saying the party always welcomed any scrutiny.
The Criminal Court accepted both cases for consideration.
It set April 22 as the date to examine the plaintiff's allegation against MC Chulcherm. It will handle the claim against the TNEWS news editor on April 29.