Acting Democrat Party leader Jurin Laksanavisit on Tuesday dismissed rumours on social media that he was in talks with the Pheu Thai Party over the possibility of the traditional arch-rivals forming a coalition government.
In a Facebook post, Mr Jurin denied his party has been discussing the party's stance regarding the formation of a new multi-party government in the wake of the March 24 general election.
He insisted it was impossible that anyone from his party had been tasked with meeting other parties to discuss this.
The rumours surfaced as a picture was circulated online of Mr Jurin and Khunying Sudarat Keyuraphan, one of Pheu Thai's three prime ministerial candidates, together. He said the photo appears to have been posted to lend more credibility to the rumours, which were false.
Mr Jurin said the picture was taken at a founding anniversary party of a newspaper on Jan 9, and was in fact published in a newspaper the following day.
Pichet Panwichartkul, a former Democrat MP for Krabi, said on Facebook that any decision to join a coalition would have to be decided by the party's executives together with the Democrat candidates who won the election and have been endorsed by the Election Commission.
But the party has yet to select its new team of executives, he said.
Meanwhile, a group of Pheu Thai MPs-elect remained adamant that they would not sign an oath to never support the National Council for Peace and Order (NCPO) or Prime Minister Prayut Chan-o-cha, according to a Pheu Thai source.
At a party meeting on March 27 the successful candidates were "asked" to sign a letter accepting the oath to ensure none would break ranks and vote for Gen Prayut to return as premier when the new parliament convenes its first meeting in the middle of May, according to the source.
But some MPs-elect did not attend. The party allegedly sent them a copy of the oath, along with a request to sign it and take a picture as proof.