Ousted Thai former Prime Minister Yingluck Shinawatra
Ousted former Prime Minister Yingluck Shinawatra smiles as she arrives at Parliament before the National Legislative Assembly meeting in Bangkok on Jan. 22, 2015. Reuters/Chaiwat Subprasom

Thailand’s ousted former Prime Minister Yingluck Shinawatra was impeached Friday for her role in overseeing a rice subsidy program, which cost the government billions of dollars. Thailand's military-appointed legislature voted to impeach Shinawatra, a decision that would ban her from politics for five years.

The impeachment could further worsen the political situation in the country, which has been under martial law since May, when the military seized power after months of protests.

The vote comes just hours after prosecutors announced separate plans to press criminal charges against her over the mismanaged multibillion-dollar program. No date has been set so far for her formal indictment, but if Yingluck is convicted, she could face a jail term of up to 10 years, The Associated Press (AP) reported. Yingluck has denied she was responsible for the corruption and has challenged the investigation committee's decision.

"The rice subsidy scheme was run by groups of people. It was a resolution of the Cabinet ... why am I singled out?" Yingluck said, during her Thursday's hearing, according to AP, adding: "To bring the case against me alone, therefore, shows a hidden agenda under an unjust practice, and is a political agenda." Of the 219 lawmakers present at the National Legislative Assembly (NLA), 190 voted to impeach her. A vote to impeach requires a three-fifths majority among NLA members.

The rice subsidy program, which promised to pay the farmers twice the market price for their products, had caused the government a loss of over $4 billion and has been marred in controversy ever since it began. Yingluck is supported by the country’s poor due to the populist programs she launched but the country’s middle and urban class claim she employed corrupt practices.

"Despite the warnings against it on several occasions, the prime minister, who should have stopped the damage, instead insisted on running the program until the damage became even more devastating," National Anti-Corruption Commissioner Wicha Mahakhun said, according to AP.

NLA members were reportedly hand-picked by Prime Minister Prayuth Chan-ocha, who had led the military coup last year. About 100 of the 220 NLA members were former or serving military officers, Reuters reported. Prayuth reportedly said he did not order the NLA to vote against Yingluck, whose brother Thaksin is also in exile.

Security near the parliament was reportedly tightened in the wake of possible protests from Yingluck’s supporters, who claim the NLA and the courts are biased.