Explainer: What's at stake in Macron's reform of France's cherished pensions?

FILE PHOTO: French President Emmanuel Macron takes part in a news conference with NATO Secretary General Jens Stoltenberg after their meeting at the Elysee palace in Paris, France November 28, 2019. Bertrand Guay/Pool via REUTERS

PARIS (Reuters) - French public sector workers began a nationwide strike on Thursday over Emmanuel Macron's plans to reform France's generous pension system, in the biggest challenge to the president since "yellow vest" protests erupted last year.

Railway workers, teachers and emergency room medics were among those joining the industrial action, which threatens to paralyse France for days. Some private sector workers also went on strike over the pension reforms.