The three-day hearing is to assess the damages Singapore Democratic Party (SDP) chief Chee Soon Juan, his sister and the SDP will have to pay for defaming Prime Minister Lee Hsien Loong and Minister Mentor Lee Kuan Yew.

The two leaders are likely to be cross-examined by lawyer M. Ravi, who is representing the SDP, as well as Dr Chee and his sister Chee Siok Chin, who are representing themselves.

If that happens, it will mark the first time that any PAP leader has been cross-examined by a political opponent in open court.

The opposition party and the Chee siblings were found to have defamed PM Lee and MM Lee in articles in their SDP newsletter two years ago.

The case began in the run-up to the 2006 General Election.

About a week before the May 6 polls, PM Lee and MM Lee had sued Dr Chee and the party's leadership for repeating remarks alleging that they were corrupt and had covered up wrongdoings at the National Kidney Foundation (NKF).

The suit stemmed from articles in the SDP newsletter, The New Democrat. It centred on the NKF saga and drew parallels between how the charity and the Government were run.

Six SDP central executive committee members apologised subsequently. But two others, Dr Chee and his sister, did not, and contested the suit.

In June 2006, the High Court ruled that the SDP - which did not file a defence in the case - defamed PM Lee and MM Lee.

Three months later, in September 2006, the Chee siblings were found guilty of defaming the two political leaders.

The Lees are seeking aggravated damages, which are exceptional awards made by the courts where the plaintiffs have been wronged severely.

The last time MM Lee was on the stand in an open court hearing was in 2004, in a separate defamation case involving Dr Chee, who failed to show up for the hearing.

PM Lee was last on the stand in 1997, in a hearing to assess the damages opposition politician Tang Liang Hong had to pay for defaming 11 People's Action Party leaders.

Over the next three days, Justice Belinda Ang will hear both sides present their case and decide on the damages to award.

The amount may not matter to the Chee siblings as they have already been declared bankrupt.

But if the SDP is unable to pay up, the 28-year-old party faces the prospect of being wound up.

However, before the hearing starts, the Chee siblings intend to ask Justice Ang to disqualify herself from the case because she gave the Lees a summary judgment in 2006 after the Chees had walked out of court.

Another matter is also pending. Lawyers for PM Lee and MM Lee have applied to strike out the affidavits of Dr Chee, his sister and former solicitor-general and opposition politician Francis Seow, on the grounds that they are scandalous, irrelevant and an abuse of process.

If their affidavits are struck out, the Chee siblings will not take the stand and be cross-examined by the Lees' lawyers.

sueann@sph.com.sg