SEOUL (AFP) - The impeachment trial of South Korea's President Park Geun Hye got under way on Thursday (Jan 5), with her lawyers arguing there is no evidence to back the corruption allegations that threaten to force her from office.

Parliament voted to impeach Ms Park last month over an influence-peddling scandal that has brought hundreds of thousands of protesters onto the streets every week demanding her removal.

Ms Park is accused of colluding with a longtime friend, Choi Soon Il, to strong-arm donations worth tens of millions of dollars from top firms which were then funnelled to dubious foundations.

She is also accused of using her influence to ensure the merger of two Samsung units in 2015 in order to help facilitate a father-to-son power succession of Samsung's founding family.

The National Assembly, which must have its vote upheld by the Constitutional Court, accused Ms Park of a serious breach of the constitution during the first full hearing in the impeachment case.

"The court is requested to fire the president so that impaired constitutional order can be restored", said Mr Kwon Seong Dong, a lawmaker representing the parliament.

"She ignored her duty as the head of state and chief administrator of the country."

The Constitutional Court's initial hearing on Tuesday (Jan 3) was curtailed after Ms Park failed to attend. It decided to proceed on Thursday (Jan 5) regardless of whether she was present.

Ms Park's lawyers urged the court to overturn the vote, saying the impeachment motion had been based on "high possibility at best" and insisted she be reinstated as president immediately.

"There is no solid evidence to back the impeachment," Ms Park's lawyer Lee Jung Hwan told the court.

Ms Park has repeatedly denied the corruption allegations in sometimes tearful televised addresses, while apologising for lapses.

In a rare meeting with journalists on Sunday (Jan 1), she said she had only sought to listen through Choi to ordinary citizens' opinion on her polices and speeches.