The Senate on Monday approved the appointment of Nopadhol Pereeroek as secretary-general of the Council of State (CoS), filling a post left vacant after Pakorn Nilprapunt stepped down in March before joining the Bhumjaithai-led government as a deputy prime minister.
The vote came after senators reviewed a report on Mr Nopadhol's background and conduct. Under Senate regulations, the discussion was held behind closed doors, drawing objections from Sen Nantana Nantavaropas.
Ms Nantana said the public should be able to scrutinise the qualifications of people appointed to key state positions.
Tension rose when she raised issues related to the Senate election investigation, prompting Deputy Senate Speaker Kriangkrai Srirak to cut her off and remind her that the debate should focus only on the nominee's qualifications.
Ms Nantana insisted she was raising concerns about transparency and called on senators whose names surfaced in the Senate election probe to refrain from voting on appointments to independent bodies until the legal process is complete.
She left the chamber immediately after making her remarks.
Sen Atcharaphan Homros, a member of the vetting committee, defended the process, saying the examination of Mr Nopadhol's qualifications was in accordance with civil service regulations.
She said the closed session was necessary to protect personal information contained in the report.
The Senate later approved Mr Nopadhol's appointment by 147 votes to none, with 22 abstentions.
