Thailand's junta-stacked parliament voted Friday to impeach former premier Yingluck Shinawatra, hours after prosecutors announced plans to indict her for corruption in a double blow that risks reigniting the country's bitter divisions.

The successful impeachment of Yingluck, the kingdom's first female premier and the sister of former leader Thaksin Shinawatra, carries an automatic five year ban from politics while the criminal charges could eventually see her jailed for up to a decade.

Experts say the impeachment and criminal charges are the latest attempt by the country's royalist elite, and its army backers, to nullify the political influence of the Shinawatras, whose parties have won every election since 2001.

But the junta's pursuit of the family could also disturb the uneasy calm that has descended on Thailand since the military took over.

The Shinawatras' 'Red Shirt' supporters, who have lain low since the coup, will be enraged by the twin decision -- although widespread street protests are unlikely given martial law banning political gatherings remains in place.

Both the impeachment and corruption charges revolve around her administration's controversial rice subsidy programme, which funnelled cash to her rural base but cost billions of dollars and inspired protests that felled her government.

A successful impeachment needed support from three fifths of the 220-seat National Legislative Assembly, a figure easily obtained with 190 voting in favour.

Frozen out

Yingluck, 47, was toppled from office by a controversial court ruling shortly before the army staged a coup in May last year.

She now faces years frozen out of Thailand's political landscape.

"The prospect of a jail term would be much more threatening and damaging to her than impeachment," Pavin Chachavalpongpun, a Thai academic at Kyoto University, told AFP.

"The primary aim is to prevent her and the Shinawatras returning to politics should the military be forced to step down and call an election. They simply cannot compete when it comes to electoral politics," he added.

Both Thaksin and Yingluck are loathed by many Thais in the upper and middle classes, but still command huge loyalty from much of the rural poor -- particularly in the Shinawatras' northern strongholds, where rice farming is a mainstay of the local economy, in what is one of the world's largest rice exporters.

The rice subsidy scheme, which purchased the crop from farmers at around twice the market rate, was hugely popular among the Shinawatras' vote base but economically disastrous, leaving Thailand with huge unsold stockpiles as regional competitors undercut their exports.

Prosecutors had spent months deciding whether Yingluck should face separate criminal corruption charges over her subsidy scheme.

"We agree that the case substantiates a criminal indictment charge against Yingluck," Surasak Threerattrakul, Director-General of the Office of the Attorney General, said Friday, adding that an indictment is expected in early March.

During the impeachment hearings, which lasted a fortnight, Yingluck defended the rice scheme as a necessary subsidy to help poor farmers who historically receive a disproportionately small slice of government cash.

She also attacked the legality of impeaching someone from a position that she had already been removed from.

Analysts said it was always unlikely that the NLA -- which is stacked with junta appointees -- would save Yingluck's political career.

Prominent protest leaders have warned against supporters hitting the streets given the ban on public gatherings. Junta leader Prayut Chan-O-Cha has also warned against such action.

"But in the medium to longer term, the grievances within the Yingluck/Thaksin side will accumulate and become more virulent when they eventually surface," Thitinan Pongsudhirak, director of the Institute of Security and International Studies at Bangkok's Chulalongkorn University, told AFP.

The decision to impeach will delight the coalition of upper and middle class Thais who led the protests that eventually toppled Yingluck's government.

Since Thaksin swept to power in 2001, Shinawatra governments have been floored by two coups and bloodied by the removal of three other premiers by the kingdom's interventionist courts.