The country's biggest political party says the regime doesn't have a mandate to send Fiji soldiers to the Golan Heights.
The Social Democratic Liberal Party says the decision to dispatch 183 soldiers almost two weeks ago and another 380 in coming weeks has been made arbitrarily.
A spokesperson, Dr Tupeni Baba, says Frank Bainimarama's decision to send Fiji troops into such danger is deplorable.
"The sending of a military contingent to a theatre of war or to any active service under the United Nations, even as peacekeepers in a new assignment, is a serious matter that should be taken only by an elected Government.
"This should be subjected to discussions in Parliament to ensure that all aspects of the issue - including the safety of personnel, the necessary provisions about their equipment, their rules of engagement and other necessary financial provisions, including health and welfare - are adequately provided for before any commitment is made."
Dr Baba told Coupfourpointfive any recommendation should have been approved by Parliament.
"It is the best way of ensuring that we take a very serious view about committing the lives of our men and women and in doing so, the Government ensures that such decision is not made lightly.
"It demonstrates also that the military is under the control of a civilian Government and bought by a Commander who is the Head of an unelected Government, who may not necessarily have the full understanding of the diplomatic and international implications of major decisions involving sending men and women in a new theatre of war."
Bainimarama had said he would send up to 500 troops when the first batch flew out, almost two weeks ago. He announced over the weekend in Honiara where he was ironically visiting the graves of five Fiji soldiers who were killed in the Second World War in the Solomons, that another 380 soldiers would leave for Golan Heights in coming weeks.
He also put his foot in it by showing off that Russia, who is reported to be trying to pull its troops out of Syria because of the danger, had offered its support - a faux paus observers say is a death warrant for our soldiers.
Dr Baba says there should be wide concern for the compromised position Fiji soldiers are now in.
"Syria is being armed by such powers as Russia and the rebels are being supported by the United States and its allies and Fiji's involvement is not only very dangerous and risky, but the military regime's recent overtures towards Russia will leave our troops vulnerable to charges that they are not neutral and independent as should be as UN peacekeepers, especially at this time in the Middle East."