A four-day hearing into a lawsuit against transport operator SBS Transit was derailed shortly after it started yesterday.

The lawsuit comes after a dispute between bus drivers and SBS over rest days and overtime pay.

Voices were raised as lawyer M. Ravi, who acts for the 13 bus drivers who are suing SBS, accused High Court judge Audrey Lim of being biased and demanded that she disqualify herself from hearing the case.

During the court proceedings, which was held via videoconference, Mr Ravi also called SBS' lawyer, Senior Counsel Davinder Singh, a "clown" while they were discussing administrative matters.

Mr Ravi said that he and his client, Mr Chua Qwong Meng, would be "discharging" themselves and that there was a breach of the right to a fair trial.

When Justice Lim asked if Mr Chua was withdrawing his case, Mr Ravi replied: "He does not want to participate any more in these unlawful proceedings."

Mr Ravi added that he would be asking "Dr Mahathir" for help as 80 per cent of the drivers are Malaysian and that he would be filing a case to the International Court of Justice.

The case was adjourned to next Monday for the judge to hear Mr Ravi's application to discharge himself.

The 13 workers claim that they had been made to work without a rest day each week and that they were underpaid for overtime work.

In June, Justice Lim said the case involved important questions of law that would affect a larger class of workers in Singapore, and allowed the case to be heard in the High Court.

The questions involve Employment Act provisions relating to the scheduling of rest days and whether bus drivers fall within the definition of workers providing "essential services".

Mr Chua's suit is being heard as a test case. This means the court's decision and findings on his suit will be binding on all the plaintiffs.

Yesterday, after the hearing started, both lawyers were given time to discuss issues relating to a particular witness.

Mr Ravi then told Mr Singh "don't be a clown, just e-mail" - meaning that he wanted the details sent in an e-mail - and said he wanted to go to the toilet.

When Justice Lim returned to the video call, Mr Singh told her that Mr Ravi had called him a clown and that they were not able to discuss the matter.

When the judge asked if this was true, Mr Ravi asked the judge if she was interrogating him.

After a while, Mr Chua, who was at Mr Ravi's office, joined the call to begin his testimony. Mr Ravi then disappeared from view and loud voices could be heard.

Mr Singh then told the court that his colleague, Mr Timothy Lin, who was at Mr Ravi's office, had been asked to leave and that a police report was being made against Mr Lin.

Mr Singh said he had written to Mr Ravi on Nov 18 to say he would be sending a representative to sit in while Mr Chua gives evidence, and that Mr Ravi did not disagree.

Mr Ravi said Mr Lin's presence was "very shocking" and a breach of privileged information as documents were laid out in the room.

Justice Lim said Mr Lin was there to ensure that Mr Chua was giving evidence without notes, and that Mr Ravi could do the same with SBS' witnesses.

Justice Lim gave Mr Ravi two options: Have Mr Lin be in the room or set up a camera to show that nobody else was with Mr Chua.

Mr Ravi asked her to disqualify herself. "You are biased because you asked Mr Singh's lawyer to come to my office," he said.

The judge declined and Mr Ravi said he would be filing an appeal.

When she asked the Mandarin interpreter to explain the situation to Mr Chua, Mr Ravi continued talking, causing the judge to ask him not to interrupt.

Mr Ravi then told the judge that he was discharging himself. He also said he was bipolar and was handling many cases.