Thailand's military-stacked legislature pushed ahead Friday with plans to impeach ousted former Prime Minister Yingluck Shinawatra in what analysts say is an attempt to neuter her family's influence in politics for good.

Yingluck, Thailand's first female premier and the sister of fellow ousted premier Thaksin Shinawatra, was removed from office in a controversial court ruling shortly before the army toppled the remnants of her elected government on May 22.

Despite being forced out of office, the military plan to impeach her over her administration's loss-making rice subsidy programme which -- while popular among her rural powerbase -- was a driving force behind protests against her now toppled government.

The kingdom's National Legislative Assembly, a loyalist body filled with junta appointees, voted Friday to bring an impeachment hearing in the New Year.

"The opening of impeachment set on January 9 at 10am and I think the whole process will take about 30 days," assembly member Jetn Siratharanont told AFP.

Yingluck's legal team had hoped to delay the hearing so they could gather more evidence but their request was denied.

Analysts say the impeachment proceedings are part of a wider campaign to make sure her family -- who are loathed by the military and Bangkok-based royalist establishment -- cannot enter office again.

"This is all part of the attempt by the junta to eliminate the Shinawatras from Thai politics," Pavin Chachavalpongpun, an expert on Thailand and staunch junta critic at Japan's Kyoto University, told AFP.

"The junta is trying to install infrastructure, through drafting a new constitution and also through a series of pending cases, to make sure that if there is ever another election someone like Yingluck -- or someone closely associated with her -- will not be able to stand," he added.

A successful impeachment needs three fifths of the national legislature to vote in favour and could see Yingluck barred from politics for five years.

The junta, which had initially hinted at an October 2015 election, said this week that fresh polls were unlikely before 2016.

May's coup was the latest chapter in Thailand's long-drawn political conflict, which broadly pits a Bangkok-based middle class and royalist elite, backed by parts of the military and judiciary, against rural and working-class voters loyal to the Shinawatras.

A Shinawatra-led or aligned government has been brought to power in every poll since 2001.