At a preliminary hearing in Prakanong Court yesterday, Mr Hall failed in a bid to have his passport returned. He resides in Burma but told judges he was not a flight risk.
The trial is expected to attract international interest because of the recent strong focus on immigrant labor in the Thai workplace via the US Trafficking in Persons report and downgrade of Thailand and a series by 'The Guardian' exposing abuses in the fishing industry.
Natural Fruit, a processing company, is suing Mr Hall for criminal defamation over an interview he gave last year to Aljazeera in Burma. It's the fourth charge brought by the company against Mr Hall.
Earlier charges were made using civil defamation and the Computer Crimes Act and include a claim for 300 million baht in compensation.
Mr Hall, who strongly denies the charges, faces lengthy jail terms if found guilty.
Natural Fruit brought charges after Mr Hall worked in researching a document entitled ''Cheap Has a High Price'' for Finnwatch, an independent organisation that focuses on global corporate responsibility issues.
Earlier this week, Lawyers' Rights Watch Canada issued a statement about Mr Hall's case and also called on the British government to intervene on his behalf.
The statement alleged that when when Mr Hall previously appeared at Prakanong Court and asked for a translator, he was told: ''If you want a translator, it's fine.
''We will imprison you in very bad conditions for a few days until we find one for you.''
Representatives from the British and Finnish embassies attended yesterday's hearing.