The French Senate is debating a bill that would make it a crime to deny that the mass killings of Armenians by Ottoman Turks nearly a century ago was genocide.
The bill -- which makes it a crime to deny examples of genocide as defined by the French state -- has sparked a diplomatic row between NATO allies France and Turkey.
Senators late in the evening of January 23 rejected a motion to dismiss the bill, paving the way for a vote.
The French lower house of parliament has already adopted the bill, which could punish offenders with up to a year in prison and 45,000 euros ($57,000) in fines.
After the National Assembly lower house overwhelmingly approved the bill in December, Turkey briefly recalled its ambassador to Paris for consultations, and suspended military and economic cooperation.
Addressing senators during the January 23 debate, the French minister in charge of relations with parliament, Patrick Ollier, pleaded in favor of the bill.
"Denial is the supreme insult to the collective memory that we share," Ollier said. "It sweeps away the peoples' suffering and condemns the victims to be forgotten. Those who encourage it are fomenting hatred that could have been and should have been extinguished with time."
At least 150 pro-Turkish and pro-Armenian demonstrators, kept apart by a large police presence, waved flags and blew whistles outside the upper chamber.
Armenia says some 1.5 million Armenians were killed in Ottoman Turkey during World War I in a deliberate policy of genocide.
Most historians agree the deaths were part of a deliberate policy of genocide.
But Turkey rejects the term and says there was heavy loss of life of both sides during fighting in eastern Turkey in 1915-1916.
France formally recognized the killings as "genocide" in 2001 but provided no penalty for anyone rejecting such a characterization. France also recognizes the Holocaust carried out against Jews and Roma by Nazi Germany during World War II as genocide.
In a nonbinding recommendation last week, a Senate panel said the bill currently under consideration was unconstitutional becomes it violates freedom of speech.
Turkish Foreign Minister Ahmet Davutoglu warned hours ahead of the January 23 vote that Turkey would take new measures against France if the Senate approved the bill.
Davutoglu did not spell out the measures Ankara would take, but said that "European values are under threat."
Davutoglu also said the bill threatens freedom of speech and that adopting it would open a "new era of inquisition" in Europe.
Turkish officials have called the bill an attempt by French President Nicolas Sarkozy to secure the votes of ethnic Armenians in this year's presidential election.
An estimated half a million Armenians live in France.
Over the weekend, thousands of Turks from across Europe marched in Paris to denounce the bill, and organizers said more protests were planned.
Sarkozy wrote to Turkish Prime Minister Recep Tayyip Erdogan last week saying the bill did not single out any country and that Paris was aware of the "suffering endured by the Turkish people" during the final years of the Ottoman Empire.
France has appealed to Turkey for calm over the Senate vote, with French Foreign Ministry spokesman Bernard Valero telling journalists that "Turkey is a very important partner and ally of France."
* CORRECTION: This story has been corrected to exclude from French-recognized "genocide" cases the mass murder of Tutsis and moderate Hutus in Rwanda in 1994.
compiled from agency reports