Seven National Legislative Assembly members, including the prime minister's brother, are being urged to resign following the disclosure of their voting records.
Sriwuwan Janya, secretary-general of the Association to Protect the Thai Constitution, on Thursday submitted a letter to Pornpetch Wichitcholchai, president of the NLA, seeking an investigation into the ethics of seven NLA members over their attendance records.
The letter was received on Mr Pornpetch's behalf by Pongsak Arunpakdisakul, deputy secretary-general of the Senate.
NLA regulations require members to attend at least one third of the votes within a 90-day period in order to remain a member unless they have submitted leave of absence letters to the NLA president beforehand.
Mr Pornpetch earlier said he assigned the Secretariat of the Senate to look into the issue which found the seven accused members had properly submitted leave of absence letters.
Their attendance data were made public by iLaw, which compiled the information in two 90-day periods from Jan 1 to June 29, 2016 based on voting results during each period. Parliamentary officials refused to give iLaw their attendance records, citing confidentiality, iLaw said on its website.
The seven are: former permanent secretary for defence Preecha Chan-o-cha, a younger brother of Prime Minister Prayut Chan-o-cha; Adm Pallop Tamisanon, a former navy chief-of-staff; Somsak Chotrattanasiri, the director of the Bureau of the Budget; Distat Hotrakitya, the secretary-general of the Office of the Council of State; Supant Mongkolsuthree, honorary chairman of the Federation of Thai Industries; ACM Jom Rungsawang, the air force chief; and, Adm Na Areenich, the navy chief.
"In the era of reform, we have to devote our time for the country's development. Performing the legislative duty, in particular, is of high importance. If they are excessively absent from attending sittings, who can the people rely on?" Mr Srisuwan asked.
Mr Srisuwan said he believed many other NLA members had done the same.
"Therefore, those who fail to attend a meeting, which requires votes to make a decision, should resign because doing so is a waste of the people's tax money. There are many other capable and knowledgeable people to work in their places.
"I want the seven NLA members to resign to show spirit and return their pays to the people. It is unreasonable to cite work overload to be absent from voting. They should not say they are wearing many hats. Being absent one or two times is acceptable, but not this many," he said.
Wanlop Tangkhananurak, an NLA member and chairman of the NLA's ethics committee, said his panel would investigate this matter only if it was asked to do so.
An NLA member found to have breached NLA regulations would be subject to various steps of penalties ranging from a deduction of the position allowance to a termination of membership, he said.
Mr Pornphet earlier said he assigned the Secretariat of the Senate to look into the issue which found the seven accused members had submitted leave of absence letters.
NLA members do not receive salaries. Instead, each one is paid a position allowance of 71,230 baht and an extra allowance of 42,330 a month, totalling 113,560 baht. If he is on any NLA committees, he receives 1,500 baht for each meeting he attends.
If a member fails to attend half of the meetings scheduled each month, he will not receive the extra allowance for that month unless he is on a parliamentary trip approved by the NLA president.
Deputy PM Wissanu Krea-ngam said two years ago that a state official may not receive salaries from more than one source but may accept unlimited position allowances and other compensation so long as the payments are not called a salary.
Each NLA member can also hire up to three experts and assistants, who are each paid 15,000 to 24,000 baht a month.