Move Forward Party deputy leader Nutthawut Buaprathum said on Wednesday there is substance to an allegation that a party MP harrassed a woman through sexual text messaging.
Mr Nutthawut, chairman of the MFP's disciplinary committee, was responding to a complaint filed with the party against Prachin Buri MP Wuttiphong Thonglour.
Mr Nutthawut said the MFP received the complaint in August, and an inquiry is underway.
The MP had not yet been invited to explain his side of the matter, as the evidence was still being compiled, he said. There was no telling how long the probe would take or when it would conclude.
He said that under newly revised MFP regulations, the executive panel must vet the matter to determine the fate of the accused MP.
The process might be time-consuming, since the two parties had given conflicting information.
“The MFP will need to explain this matter to meet people's expectations. Every procedure will proceed based on the evidence,” said Mr Nutthawut.
Asked if there were grounds to the allegation against Mr Wuttiphong, he said the party was of the opinion there were grounds to the complaint. The victim had shown courage and confidence and had supplied sufficient information to file a petition with the party, he said.
Any punishment would be decided on the gravity of any wrongdoing, he said. The party could either expel the MP or suspend him from standing at the next election if the allegation was considered accurate.
Mr Nutthawut said the MFP had strict screening criteria for its candidates. In some cases, screening began even before they became members.
However, the party could not evade responsibility for the behaviour of its members.
The MFP regularly organised workshops to educate members and poll candidates about gender equality. He said two lawyers, Sasinan Thamnithinan and Nittaya Meesri, with experience in related legal affairs, had joined the disciplinary committee.
“We are not dragging our feet, but we must take the time to inspect the evidence thoroughly before a decision is made,” he added.
House Deputy Speaker and former MFP member Padipat Santipada said a parliamentary inquiry may be launched if a formal complaint is lodged against the MP.
Parliament has not yet set up its ethics committee, pending the naming of the new opposition leader, he said.