Thailand's military-appointed parliament voted to impeach former prime minister Yingluck Shinawatra for her role in overseeing a government rice subsidy programme that lost billions of dollars.
The vote means that she will be banned from politics from five years.
It came just after the attorney general's office announced separate plans today to indict her on criminal charges for negligence related to losses and alleged corruption in the rice scheme.
No date has been set for the formal indictment, but if convicted Ms Yingluck could face 10 years in jail.
Her supporters see the moves as part of an effort to deal a final blow to her party's political power after last year's army coup.
Analysts say it may further polarise a nation plagued by political turmoil and coups for the last decade.
Impeachment required a three-fifths vote of parliament's 220 members, and 190 voted against Ms Yingluck.
Most members are part of the military, or political opponents of Ms Yingluck and past governments allied with her brother, former prime minister Thaksin Shinawatra, who was ousted in a 2006 coup.
Ms Yingluck did not immediately comment, but in an appearance before parliament yesterday she denied she was responsible for any corruption and questioned the fairness of an investigation by the anti-corruption commission, which had recommended she be charged.
She said: "The rice subsidy scheme was run by groups of people. It was a resolution of the Cabinet ... why am I singled out?
"To bring the case against me alone, therefore, shows a hidden agenda under an unjust practice, and is a political agenda."
She also said the anti-corruption commission lacked the legitimacy to judge her because the junta terminated the constitution when it took power on May 22.
National anti-corruption commissioner Wicha Mahakhun said yesterday that Ms Yingluck was to blame.
He said: "Despite the warnings against it on several occasions, the prime minister, who should have stopped the damage, instead insisted on running the programme until the damage became even more devastating."
The rice subsidy programme, which paid farmers double the market price for their crops, ultimately incurred national losses of more than 4 billion US dollars (£2.6 billion) and temporarily cost Thailand's place as the world's leading exporter.
Supporters say the programme was intended to benefit Thai farmers and reduce the income equality gap in the country. The policy had helped Ms Yingluck's government win power in 2011.
Surasak Threerattrakul, director general of the attorney general's department of investigation, said today that Ms Yingluck will also face criminal charges for negligence of duty as a state official overseeing the programme.
He told reporters at a news conference in Bangkok that the attorney general had examined evidence and testimony against Ms Yingluck "and found that the case was complete enough to prosecute".