Former deputy premier Anwar Ibrahim will hear tomorrow whether he will be freed after nearly six years in prison or remain behind bars until at least 2009.

On the anniversary of his shock sacking by then-prime minister Dr Mahathir Mohamad on Sept 2, 1998, the country's highest court is due to deliver its verdict on his last-chance appeal against a conviction for sodomy.

If Anwar wins, he will walk free since he has already completed a sentence for corruption and begun serving his nine-year term for sodomy.

If he fails, he will remain in jail for another five years, even with a one-third remission of sentence for good behaviour.

"Hope is there, but given the past decisions, he is not optimistic," Anwar's lawyer Sankara Nair told AFP.

"Given the disappointments he has faced all these years, he has no confidence."

Nair said there was some speculation that Anwar would be acquitted, but dismissed this as "unconfirmed rumours".

Medically unfit

Anwar has insisted he will be in the Federal Court to hear the verdict against the advice of his doctors, who say he is medically unfit to attend the hearing, Nair said.

He was admitted to hospital in July after suffering complications from a damaged spinal disc which he blamed on a police beating after his arrest in 1998.

Anwar was detained shortly after being sacked by Mahathir. He says the charges against him were trumped up to prevent him from making a challenge for the leadership as thousands took to the streets in protest.

He appealed against his conviction and sentence for sodomy on the grounds that the trial was deeply flawed, but from the start of the hearing in May he has expressed pessimism over the outcome.

Anwar told reporters in court that incumbent Prime Minister Abdullah Ahmad Badawi, who took over when Mahathir retired last October, was continuing to control the judiciary and that the judges were biased against him.

His lawyers, who say Anwar is the victim of a political conspiracy, asked the judges to "focus on the weird and bizarre events" in the trial, such as the changing of the date of the alleged offence and the refusal to allow a fresh alibi.

The original charge stated that Anwar sodomised Azizan Abu Bakar, an official government driver, one night in May 1992. This was changed to one night in May 1994 after it was found the condominium where the event allegedly took place did not exist at that time.

Prosecutors later again changed the date to "sometime between January and March 1993".

International condemnation

The conduct of the trial was widely condemned internationally, and Anwar is considered a political prisoner by human rights groups and the United States, although interest in his plight has clearly waned over the years.

The Keadilan party, launched to press Anwar's cause after his sacking, was virtually wiped out in March elections, with only his wife Wan Azizah Wan Ismail winning a seat in parliament.

Anwar's supporters had hoped that Mahathir's retirement presented a chance for him to receive a pardon or at least what they would consider a fair hearing in court, but these hopes have faded.

While his case is no longer in the international spotlight, Amnesty International joined Human Rights Watch and the International Commission of Jurists to issue a joint call at the start of the appeal for Anwar to receive a fair hearing.

"It is time that the injustices that marked the arrest, trial and imprisonment of Anwar Ibrahim be set right," the three groups said in a statement.

The Federal Court in 2002 rejected Anwar's appeal against the corruption charge. This accused him of abusing his official powers to cover up allegations of sexual misconduct.