Thailand's military-appointed assembly spared 38 former senators from impeachment on Thursday, after two weeks of scrutiny over a legal amendment they had supported in 2013.
The former senators were earlier indicted by National Anti-Corruption Commission (NACC) for supporting a 2013 Bill to change the then half-elected Senate to a fully elected one.
In November that year, the Constitutional Court outlawed the change, arguing that it would destroy the "checks and balances" in the political system.
Former prime minister Yingluck Shinawatra was impeached by the same assembly in January for failing to put a stop to a rice subsidy scheme estimated to cost more than 500 billion baht (S$21 billion). That disqualified her from politics for five years.
Meanwhile, the Attorney-General's Office has filed criminal charges against her over the same issue, which could result in her being jailed for up to 10 years.
Yingluck was ousted from office by a Constitutional Court ruling shortly before her government was thrown out a military coup last May. Like Yingluck, the former senators had stopped holding office since then, as the military abrogated the sitting Constitution and dissolved the Senate.
Since taking over, the military has clamped down on dissent and steadily dismantled the power network of Yingluck's brother Thaksin Shinawatra. The tycoon, who has been accused of using her sister as a proxy, was ousted from his premiership by a coup in 2006 and lives abroad to evade a graft related jail sentence.
Separately, the NACC is considering whether to push for the impeachment of 250 former members of Parliament. It has already indicted them for supporting the Senate amendment bid.
The moves are expected to further erode Thaksin's political reach in the country.