Cmdr Bainimarama has put off elections until 2014
Fiji has jailed eight men for between three and seven years for attempting to kill the country's military leader, Commodore Frank Bainimarama, in 2007.
Sentencing the men, Justice Paul Madigan said had the men's plot succeeded the consequences for the Pacific nation were "unthinkable".
But critics have said the men did not have a fair hearing in court.
Cmdr Bainimarama seized power in Fiji in a 2006 coup and has said elections can only be reinstated in 2014.
The eight men were arrested in November 2007 over the alleged plot against Cmdr Bainimarama and four senior military and cabinet officials.
Justice Madigan said Fiji had been in "a very fragile state" at the time of the plot.
"Had this plot succeeded, the consequences are unthinkable," the Associated Press news agency quoted him as saying.
"There has been no evidence before this court of any thought given to the fate of the average Fijian should the country be suddenly rid of its president, prime minister and army.
"The plans of the accused were totally self-serving, thoughtless and greedy."
Elections on hold
The longest sentences were given to indigenous leader and former politician, Ratu Inoke Takiveikata and businessman Sivaniolo Naulago.
New Zealander Ballu Khan was also arrested in 2007, but had charges against him dropped.
He said the men had never plotted to kill the leaders.
"We are dealing with Fijian judiciary here. It's not an independent judiciary," Mr Khan told Radio New Zealand.
"None of them should be going to jail, they should have never been tried in the first place. The military people should have been in the dock and being charged."
Mr Bainimarama became interim prime minister of Fiji in 2007 and pledged to hold elections within two years.
But he has since said constitutional reforms are needed and he not now call elections until 2014.
Critics charge that under Cmdr Bainimarama's rule, Fiji has suspended the constitution, detained opponents and suppressed freedom of speech.