Mr Singthong said in the complaint that Mr Surachai, as senate deputy speaker, had proposed a royal decree for an extraordinary Senate meeting from May 2-10 specifically to endorse the appointments of a judge of the Administrative Court and a member of the National Anti-Corruption Commission.
Mr Surachai also put an additional item on the meeting agenda, the election of the new Senate speaker. Mr Surachai himself was elected to the position of Sepate speaker.
This violated the royal decree for the extraordinary Senate meeting, the Senate meeting regulations and Section 122 of the constitution regarding conflicts of interests, Mr Singthong said.
The Pheu Thai member said he would also file a petition against Mr Surachai with the National Anti-Corruption Commission.