Another two key members of the Democrat Party have resigned their membership following the party's general assembly on Saturday.
During the assembly, Chalermchai Sri-on was elected leader along with a new executive committee.
The latest two members to quit the party that was formed in 1946 are Sathit Wongnongtoey, a former Trang MP, and Ornanong Kanchanachusak, a former Bangkok MP.
Both are former members of the Democrat Party's executive committee.
Mr Sathit on Monday posted notice of his resignation on Facebook:
"I had been thinking hard about this for the past two days. Although I still adhere to the party's ideology, the soul and spirit of the Democrat Party no longer exist. After consulting with colleagues with whom I have worked hard in the party for over 28 years, I decide to resign my party membership."
Ms Ornanong also posted on Facebook, announcing her resignation. She said that throughout her 25 years in politics her allegiance had been to the Democrat Party. "But today I have decided to resign from the party - a decision which goes against my feelings for the party I love the most."
She was full of praise for former party leader Abhisit Vejjajiva, saying he was her model politician.