The Pheu Thai Party will hold a meeting on Monday to select new executive board members to replace Sompong Amornwiwat and Khunying Sudarat Keyuraphan after they resigned from the board.
Mr Sompong was the party's leader, while Khunying Sudarat was chief strategist. They, and a handful of other key members, resigned from the Pheu Thai strategic committee earlier last week. The reason given is they want to encourage reform in the party.
The others were former parliament president Pokin Polakul, former finance minister Kittiratt Na-Ranong, former deputy premier Pongthep Thepkanjana and former deputy commerce minister Wattana Muangsook. They are all still members of the party.
Mr Sompong, who is opposition leader, has yet to announce his resignation, but he's already met many high-ranking party officials at parliament to say his farewell. Earlier, he spoke about Khunying Sudarat's resignation, saying the news about her leaving her post was alarming since the chief strategist was an important person in the party.
Khunying Sudarat worked tirelessly and fought for the party, he said, adding he has not been in touch with her since the resignation and hopes to speak with her.
Sources said Mr Sompong still has a chance to backtrack on his resignation since he is still opposition leader. The constitution stipulates an opposition leader must be a party leader with the most MPs at the House. Mr Sompong is the oldest MP and a respected figure in the Pheu Thai Party.
Mr Wattana wrote on his personal Facebook page that he has decided to leave the strategic committee after Khunying Sudarat, Mr Pokin and Mr Pongthep quit. He said he is still a member of the Pheu Thai Party and was ready to fight for democracy.
In addition, Pheu Thai MP for Bangkok Jirayu Huangsap also resigned from his deputy secretary-general post.
Sudarat: Rumours come true
All eyes are now on Capt Anudith Nakornthap, the party's secretary-general, who is close to Khunying Sudarat.
Pheu Thai MPs, particularly those representing northeastern provinces, reportedly suggested that a meeting be held for Khunying Sudarat to inform all party members of the real reason for her resignation.
In January, there were widespread news reports of her resignation.
A Pheu Thai source said the reports were untrue and whoever made up the story was out to destabilise and sabotage the party.
Earlier, there was also talk about a possible resignation of Mr Sompong.
If he resigned, the current executive board of the party would have to leave to pave the way for a new board, sources said.
Some believe that Capt Anudith, the secretary-general, might be replaced by a Pheu Thai MP who is close to former prime minister Thaksin Shinawatra.