Muhammad Abbou, 39, was arrested in early March after the publication of an article on the Tunisnews website which criticised President Zine El Abidine Ben Ali for inviting Israeli Prime Minister Ariel Sharon to attend a technology summit.

Abbou was handed a one-and-a-half-year prison sentence in April for attempting to "disrupt public order" by writing in a separate report in mid-2004 that Tunisian prisoners faced a similar plight to the Iraqis who were abused by US troops in Baghdad's notorious Abu Ghraib prison.

He was also sentenced to two years in jail for the assault of a female lawyer, who claims to have been permanently disabled by the attack.

His appeal is due to be held on Friday.

The conviction triggered protests from the Tunisian bar association and human rights groups who have denounced his trial as a move to quash opposing political views.

Last month, Abbou went on a hunger strike for several days to protest against his lawyers being barred from visiting him at the Kef prison in northwest Tunisia where he is being held.

Ben Ali's authoritarian government has a widely criticised human rights and press freedom record.