Thai PM Yingluck Shinawatra has appeared before the Constitutional Court in Bangkok to defend herself against allegations of abuse of power.
The complaint was filed by senators who said Yingluck Shinawatra’s party benefited from improperly transferring her national security chief in 2011.
Yingluck Shinawatra could be removed from office and banned from politics for five years if found guilty.
Thailand has seen deadlock since anti-government protests began in 2013.
The protesters, who are mainly urban and middle class, want Yingluck Shianwatra’s government replaced by an unelected “people’s council”.
In response, Yingluck Shinawatra called a snap election in February which she was expected to win, but this was disrupted by the protesters and subsequently annulled.
The prime minister is also facing several legal challenges.
Earlier this year, a different court ruled that Yingluck Shinawatra had improperly transferred national security chief Thawil Pliensri in 2011.
Thawil Pliensri has since been reinstated, although he was originally appointed by the previous administration and has been openly critical of Yingluck Shinawatra’s government.
The Constitutional Court will decide whether his transfer violated the constitution.
“I deny the allegation… I didn’t violate any laws, I didn’t receive any benefit from the appointment,” Yingluck Shinawatra told the court on Tuesday.
She added that replacing Thawil Pliensri was for Thailand’s benefit.
Yingluck Shinawatra also faces charges of negligence over a government rice subsidy scheme which critics say was rife with corruption.
Her supporters believe the top courts are biased against her and the cases are an attempt by the elite to force her from office.
Last week, Yingluck Shinawatra’s government announced fresh polls on July 20, but the opposition has rejected the date.