PARIS—French Prime Minister Michel Barnier faces a pivotal no-confidence vote Wednesday that risks toppling his government and derailing France’s efforts to get its public finances back on track. Barnier’s government,

The French government is barreling toward a collapse that would plunge the country into political chaos and could have economic ripple effects in Europe.

Far-right and left-wing lawmakers joined forces to back a no-confidence motion against Prime Minister Michel Barnier and his government, with a majority of 331 votes in support of the motion.