The majority of senators who signed a petition seeking Prime Minister Srettha Thavisin's ouster over the controversial decision to appoint Pichit Chuenban as PM's Office Minister would rather remain unidentified, but they are not acting on behalf of anyone, according to a senator.
Direkrit Janekrongtham admitted he is one of the 40 senators.
He said the constitution allows the Senate to submit such a motion with the support of at least one-tenth of the 250 senators, or 25.
Mr Direkrit said each senator has the right to withhold their names. "Some don't want the media attention," he said.
Although the junta-appointed senators' five-year term expired on May 10, they remain in office and retain their power to scrutinise the government until the next batch of senators assumes office.
"The senators did not receive any instruction from anyone [to submit a petition against the prime minister].
"Several senators hold different opinions and can make their own decisions," Mr Direkrit said.
Senate speaker Pornphet Wichitcholchai, who forwarded the senators' petition to the Constitutional Court, yesterday refused to give the names of the senators.
Last week, a group comprising 40 senators asked the court to rule on the status of Mr Srettha and PM's Office Minister Pichit after the latter was appointed to the post in a recent cabinet reshuffle.
The petition asks the court if Mr Srettha and Mr Pichit should be terminated from their positions under Section 170 (4) and (5) of the charter, which deals with the ethics of cabinet ministers.
The appointment of Mr Pichit, who served as ex-prime minister Thaksin Shinawatra's former lawyer, as the PM's Office Minister raises questions about his eligibility to serve as a cabinet minister.
This is because he served time in jail for contempt of court over an attempted bribery case when he represented Thaksin in a controversial land case back in 2008.
On June 25, 2008, the Supreme Court sentenced Mr Pichit and two of his colleagues to six months in prison after they tried to bribe Supreme Court officials by handing them a paper bag containing 2 million baht in cash a fortnight earlier.
All three represented Thaksin and his ex-wife, Khunying Potjaman na Pombejra, in the Ratchadaphisek land case, for which Thaksin was sentenced to two years in prison in 2008.