AL JAZEERA'S HARRY FAWCETT, REPORTING FROM SEOUL: Nearly a month after the national assembly voted to impeach President Park, the constitutional court is at last hearing the arguments on both sides. Lawyers for the national assembly are essentially rethreading the language of the impeachment motion saying that the president is not deserving of her office, that she gravely broke the constitution by allowing a long-time friend to intervene in the running of state affairs among other things. We are also now finally hearing a detailed defence from Park's legal team, going point by point through the various allegations against her. For example she wasn't aware that her friend Choo Soon-sil was involved in cultural and sporting foundations to which she was encouraging large corporate giants to donate millions of dollars. They are admitting one mistake, saying that she did allow Choo Soon-sil access to presidential speeches but that her influence was tiny and was not systemic. They are saying it was a small mistake that was not grave enough to lose Park her office.

South Korea's Constitutional Court has begun to hear oral arguments in the impeachment trial of President Park Geun-hye, who politicians voted to remove over a corruption scandal that saw millions of people protest over the past several months.

Park's lawyers and lawmakers, who serve as prosecutors in the trial, traded pointed arguments on Thursday on the validity of accusations that she colluded with a confidante to extort money and favours from companies and allowed the friend to unlawfully interfere with government affairs.

READ MORE: Park Geun-hye says she has never conspired with anyone

Lawmaker Kweon Seong Dong, the chief prosecutor in the trial, said Park betrayed the trust people put in her by "broadly and gravely" violating the constitution and criminal laws.

Park's lawyer, Lee Joong-hwan, said the accusations stated in the impeachment bill "lack evidence and fail to make legal sense" because they were based on allegations and media reports, not criminal convictions.

The hearing proceeded without Park, who refused to testify for the second time following her no-show on Tuesday. The nine-justice court cannot force Park to appear.

Park's lawyers may prefer her not to testify because their chief argument is that the accusations against Park have not been fully proven, Han Sang-hee, a law professor at Seoul's Konkuk University, told the AP news agency.

Park rejected requests by state prosecutors to question her and has yet to be questioned by the special prosecution team that has taken over the inquiry.

The court, which will hear witnesses later on Thursday, has six months to decide if Park should permanently step down or should be reinstated.