Another French opposition figure, prominent centrist politician Francois Bayrou, said in an open letter published in Sunday's Journal du Dimanche that it would be "unthinkable" for Hollande to act without consulting parliament.
Voices from within Hollande's own party agreed. The head of parliament's defense committee, Patricia Adam, told the newspaper that she favors the idea on a personal level, and that she "doesn't see any reason why parliament wouldn't get a say now when others do."
In what looked like a nod to these calls for more parliamentary oversight, Prime Minister Jean-Marc Ayrault said Sunday he would meet with leaders of the parliament's defense and foreign affairs committees as well as parliamentary party leaders on Monday to discuss the Syria situation.
Other Socialists, including Interior Minister Manuel Valls and the head of parliament's foreign affairs committee Elisabeth Guigou, took to Sunday's TV chat shows to reiterate the government's stance, backed up by the constitution, that it is Hollande's prerogative to take the decision for military action.
"We don't change the constitution based on someone's mood or on what's happening in the world," Valls said on I Tele.
France has echoed U.S. calls for a strong international coalition to take action in Syria, and Valls reiterated Sunday that there is no question of France going it alone in the event the U.S. Congress rejects Obama's call for action.
Should Hollande decide to heed the calls for a vote, experts said there are two possible scenarios.
One would be for Prime Minister Jean-Marc Ayrault to make the question part of a confidence vote on his government. That was done in 1991, when parliament backed then-President Francois Mitterrand's decision to join the U.S-led coalition in the Gulf War. A no-vote, although unlikely given the Socialists' majority in parliament, would bring down the government.
Another article of France's Constitution gives the government the option of holding a non-binding vote on any question proposed either by the government itself or by a parliamentary group.