A panel of three Fiji judges headed by the acting chief Justice, Anthony Gates, is today due to read the judgement on the legality of the interim regime.
The case was brought by the ousted prime minister, Laisenia Qarase, and heard in March.
The judges had reserved their decision but are now due to read it out today.
It will determine whether the military commander, Commodore Bainimarama had the powers to remove the President from office and assume executive authority of the country when he carried his 2006 coup.
Mr Qarase had claimed that the action was unlawful and therefore the interim regime was non-existant and illegal.
He hopes the outcome will follow the precedent of 2000 when a court ruled that the constitution was not abolished as claimed by the then coupmakers led by George Speight.
At the weekend, Commodore Bainimarama said the work done by the interim regime now is not about legality or illegality but about building the nation.