Turkey has threatened to publicly attack France's colonial past if Paris makes denying Ottoman Turks' First World War killings of Armenians a crime.
Historians estimate up to 1.5 million died in deportations in 1915-16. Turkey puts the number of deaths closer to 300,000 and denies it was genocide.
France's lower house of parliament will today consider making the denial of the atrocity a crime carrying a £37,000 fine and one year in jail.
The issue threatens to further damage relations between the two countries, which are already tense over French leader Nicolas Sarkozy's opposition to Turkey's bid to join the EU.