BANGKOK - Thailand's besieged Prime Minister Yingluck Shinawatra is due to appear in front of the nation's Constitutional Court on Tuesday facing allegations of abuse of power that could see her sacked from office.
The case, one of two potential knockout legal moves against her premiership, comes as Thailand's political crisis reaches a critical juncture with anti-government protesters still massed on Bangkok's streets -- although in diminished numbers -- and Yingluck's supporters also threatening to rally to defend her.
The complaint was filed to the court by a group of senators who said that the replacement of then-national security chief Thawil Pliensri after Yingluck was elected in 2011 was for the benefit of her party.
Under the constitution -- forged after a 2006 coup that ousted Yingluck's billionaire brother Thaksin Shinawatra as premier -- such an offence could lead to her removal and a ban from politics.
It was unclear whether Yingluck will attend as ordered by the court along with three others who are due to give testimony, including Thawil.
The court has not given a date for its ruling but a member of Yingluck's legal team urged the nine-member appointed court to give the case more time.
"We have asked for five more witnesses... the court has not yet made a decision on that request," he told AFP on Monday, requesting anonymity.
The court could also extend its verdict to key cabinet members who endorsed the decision to remove Thawil, potentially dislodging a layer of ruling party decision-makers with ties to Thaksin, who lives overseas to avoid jail for corruption convictions.
Six months of political street protests have so far failed to force Yingluck from office.
But observers say the legal challenges appear poised to end her administration.
Yingluck has also been charged by the National Anti-Corruption Commission (NACC) with neglect of duty in connection with a costly and bungled rice subsidy scheme that critics say fomented rampant corruption.
If indicted on those charges, Yingluck would be suspended from office and face an impeachment vote in the upper house of parliament that could lead to a five-year ban from politics.
"If the Constitutional Court does not rule against Yingluck -- which I think it will -- then the NACC will at least impeach her and she would have to step down while the Senate decides on convicting her," said Paul Chambers, director of research at the Institute of South East Asian Affairs at Chiang Mai University.
Critics accuse the Constitutional Court of rushing through Yingluck's case and allege previous rulings show that it is politically biased against the Shinawatras.
In 2008, the court forced two Thaksin-linked prime ministers from office.
The Constitutional Court in March nullified a February general election disrupted by protesters, leaving the kingdom in legislative limbo with only a caretaker government.
Thaksin-allied parties won every previous election for more than a decade, helped by strong support in the northern half of the kingdom.
Election authorities and the ruling party have agreed on July 20 for new polls to find a way through the political paralysis, which has chiselled away at Thailand's once-dynamic growth.