A senior Thai legislator has been forced to apologise after two gay men kissed at a press conference in parliament on Wednesday.

The conference was held by the Future Forward party to highlight Thailand’s marriage laws, with LGBT coordinator Ekkawat Pimsawan ceremoniously submitting a proposal calling for a legal change to allow same-sex marriage.

TV footage of the conference shows an MP standing next to the two men, James Panumas and Tattep Ruangprapaikitseree, and applauding as they embraced. The simple kiss was so extraordinary that it sparked widespread accusations of “improper” behaviour in parliament.

Senator Somchai Sawengkarn reportedly wrote on Facebook that he found the incident too shameful and beyond forgiveness, and urged parliament to probe the ethics of the MPs and the House committee concerned.

House speaker’s secretary Tankhun Jit-Issara said: “There are rules for using the press conference room that prohibit inappropriate language, insults, slander and indecent behaviour. Furthermore, users must maintain polite manners at all time in the establishment and follow other stated rules strictly.”

Parliament President Chuan Leekpai has demanded a report on two men and will later decide on what “punitive action” should be taken against those who arranged the event.

MP Mukda Pongsombat, who chairs the committee, was forced to issue an extensive apology for the display of public affection, and promised it would not be repeated.

“As the chairwoman, I accept a lack of prudence, but it was unexpected,” she said. “The committee did not plan for such incident to happen and we are sorry that the incident affected the image of the House of Parliament. I will admonish the persons involved and make sure that such an incident never happens again.”

She added: “While we are within our rights to express ourselves, we should also show respect for the venue.”

Thailand is often viewed as a very LGBT-friendly country, but public sentiment is not always so liberal. Thai law currently does not recognise same-sex marriages, civil unions, or domestic partnerships, although LGBT+ activists are fighting for this to change.