The United Front For a Democratic Fiji says there is genuine concern that elections promised for next year won't be held.
The group, which represents many of those who were removed from office in the 2006 military coup, says the regime is delaying the electoral process by delaying the constitution.
It says the regime leaders, Commodore Frank Bainimarama and Aiyaz Sayed-Khaiyum, have sensed that the regime has very little, if any, support.
In January, Commodore Bainimarama announced that the regime's draft would be ready for deliberation by the end of January and the new constitution in place by end of March.
The United Front For a Democratic Fiji says the date was first moved to end of April, then to end of July and now it is pushed back to September.
It adds that the two regime leaders fear that they will have a lot to answer for when the rule of law is re-established in Fiji.