France's parliament was set for a fiery debate on military action in Syria Wednesday as pressure mounts on President Francois Hollande to follow Washington's lead and put the issue to a vote.
Hollande is under no obligation to obtain parliamentary approval for action, but with public opinion deeply sceptical of military strikes, many lawmakers are clamouring for a vote.
The public is as well, with a poll released on the eve of the debate showing nearly three quarters of the French saying they want a vote on military action.
"The debate is going to be tense," newspaper Liberation wrote Wednesday. "After (US President) Barack Obama's decision to consult Congress... Francois Hollande should make parliament vote to establish the legitimacy of his action."
Hollande's government has not ruled out a vote, but he will be keen to avoid an embarrassing rejection of military strikes like the one suffered last week by British Prime Minister David Cameron.
France has vowed to "punish" Syrian leader Bashar al-Assad for an alleged chemical weapons attack on August 21 and this week released an intelligence report pinning the blame for the assault on the regime.
In a letter to French lawmakers, Syria's parliament speaker on Wednesday urged them not to support military action.
"We ask you not to hasten to commit a heinous, senseless crime, as you must steer the French republic away from the war path and towards diplomacy," Jihad Lahham said in a statement published by the SANA official news agency.
The French debate comes as Obama lobbies Congress to back US strikes when it returns from its summer break on Monday.
France has emerged as the key US ally in taking action against Assad's regime, after Britain's House of Commons rejected military action.
Hollande's Socialists are largely supportive of strikes, but other leading parliamentary factions have raised doubts, including the main opposition right-wing UMP.
The UMP has said military action should be put to a vote unless two conditions are met: UN inspectors confirming the use of chemical weapons and the passing of a UN resolution giving a legal basis for using force.
The head of the UMP's faction in the lower house National Assembly, Christian Jacob, said Hollande did not yet have the clear-cut legitimacy to order military strikes.
"(France) is isolated as it has never been before, is not supported by any European country and is dependent on a vote of the US Congress," he said.
The debate, expected to last about two hours, was due to start at 1400 GMT, with Prime Minister Jean-Marc Ayrault addressing the National Assembly and Foreign Minister Laurent Fabius appearing before the upper house Senate.
The divisions in France over action in Syria are in sharp contrast to the widespread support Hollande enjoyed when he launched a military intervention in Mali earlier this year.
The Mali operation, which saw French troops push back Islamist rebels who had seized the west African country's vast desert north, was launched without any thought of holding a parliamentary vote. Four months later, its continuation was backed without any votes against.
The Mali intervention was widely backed by the public however, unlike a military intervention in Syria, which a recent poll showed is opposed by 64 percent of the French.
The minister in charge of relations with parliament, Alain Vidalies, said a vote on Syria was "possible" and that "the subject is not taboo".
But senior Socialists have made little secret of their distaste for a vote.
"There is no question of imposing a vote on the president," National Assembly speaker Claude Bartolone said, adding that "the moment when a dictator is threatening France" is not the time to change how the country decides to take military action.