Chat Thai Party leader Banharn Silapa-archa assigned a close aide to lobby the Phya Nak Faction led by Pinij Charusombat and Preecha Laopongchana, which has about 40 members to join the party, the source said.

Chat Thai Party deputy leader Weerasak Khosurat said the party welcomed new members but it also depended on their conditions. Secretary-general Prapat Photasuthon said there have been negotiations with factions from Thai Rak Thai Party but they are not yet clear.

A Chat Thai source said a faction led by Sonthaya Kunplome, comprising 10 people, and another group led by Suchart Tancharoen, contacted Chat Thai in April last year, when the Thai Rak Thai Party was experiencing internal fighting. However, they did not defect because of the 90-day party membership rule. The source said it was certain the two groups would run in the next election under Chat Thai's banner.

The Wadah faction led by Wan Muhamad Noor Matha, also wants to join Chat Thai but Banharn is thinking hard because this group had quarrelled with Chat Thai's Kuheng Yaworhasan.

Democrat Party secretary-general Suthep Thaugsuban said some former Thai Rak Thai Party MPs wanted to join his party but he refused to name them. "They have to go through the process of our party. Party defection is a normal scenario in politics,'' he said.

Mahachon Party deputy leader Akapol Sorasuchart said the party had not contacted any former MPs to join it because it has a policy of bringing in new generation candidates. But if any former MPs wanted to join, it would consider them on a case-by-case basis.

Thai Ground Party deputy leader Sarit Santimethanidol said many former Thai Rai Thai Party MPs wanted to join the party but he refused to elaborate.