The main opposition People's Party has petitioned the National Anti-Corruption Commission (NACC) to investigate allegations that a senior Interior Ministry official used a Line chat group to instruct subordinates to support candidates from the Bhumjaithai Party during the Feb 8 election campaign.
People's Party deputy leader Wiroj Lakkhanaadisorn, Phuket MP Chalermpong Saengdee and lawyer Phattarapong Supakson submitted the complaint to the anti-graft agency on Tuesday, calling for an inquiry into leaked chat messages purportedly linked to Department of Provincial Administration (DPA) director-general Narucha Kosacivilize.
The controversy centres on a message allegedly sent by the DPA chief instructing subordinates to "help the blue side", a phrase widely understood in Thai politics as a reference to Bhumjaithai, whose party colour is blue.
Mr Wiroj said the authenticity of the messages could be verified through digital forensic examinations, including checks on phone numbers linked to the relevant Line accounts.
"If cyber police or Line Thailand are asked to assist, verification could be completed within days," he said.
"The key issue is not whether there are minor inaccuracies in the leaked screenshots, but whether the director-general actually sent messages to his subordinates and whether the phrase 'help the blue side' appeared in those communications."
Civil servants are legally required to remain politically neutral and must not use state authority to favour any political party or candidate, he said.
Mr Wiroj said Mr Chalermpong would also file a separate complaint with the Election Commission seeking an investigation into possible violations of election laws.
Mr Chalermpong alleged that political interference by state officials in Phuket extended beyond the leaked chat messages and reflected a broader, organised effort to support Bhumjaithai candidates during the election.
According to him, some civil servants who refused to comply with political directives were transferred or faced disciplinary action. He alleged that one district official had been unfairly targeted after failing to deliver a desired election result.
He also questioned why Prime Minister and Interior Minister Anutin Charnvirakul had yet to establish a formal investigation into the allegations, despite repeatedly emphasising the need for political neutrality among civil servants.
Mr Phattarapong said he had already filed a criminal complaint against the DPA chief with the Region 8 Criminal Court for Corruption and Misconduct Cases.
He said the matter is also expected to be considered by a House committee on political development, mass communications and public participation on June 11.
Separately, People's Party list MP and spokeswoman Pukkamon Nunarnan posted another alleged Line chat screenshot on social media on Tuesday.
The message was purportedly posted by a district official in Phuket in a group for territorial defence volunteer trainees and appeared to endorse a Bhumjaithai candidate during the election campaign.
