Thousands protest in France against new prime minister

Protests took place in Paris as well as other cities including Nantes in the west, Nice and Marseille in the south and Strasbourg in the east.

Macron on Thursday appointed Barnier, a 73-year-old former foreign minister who acted as the European Union's Brexit negotiator, as prime minister, seeking to move forward after July snap elections in which his centrist alliance lost its relative majority in parliament.

Barnier said on Friday night that he was open to naming ministers of all political stripes, including "people from the left".

But a left-wing coalition, which emerged as France's largest force after the elections, although without enough seats for an overall majority, has greeted Macron's appointment of Barnier with dismay.

On Saturday, many demonstrators directed their anger at Macron and some called on him to resign.

"The Fifth Republic is collapsing," said protester Manon Bonijol. "Expressing one's vote will be useless as long as Macron is in power," added the 21-year-old.

Hard-left leader Jean-Luc Melenchon, whose France Unbowed party (LFI) and allies belong to the left-wing bloc, has charged that the election had been "stolen from the French" and called on French people to take to the streets.

On Saturday, he urged supporters to prepare for battle. "There will be no pause," he vowed.

"Democracy isn't just the art of accepting that you've won, it's also the humility of accepting that you've lost," Melenchon said from a truck at the Paris protest.

The left-wing alliance wanted Lucie Castets, a 37-year-old economist, to become prime minister, but Macron quashed the idea, arguing that she would not survive a confidence vote in the hung parliament.

Police expected up to 8,000 people to protest in Paris. Smaller protests took place in other cities across France.