PARIS, (Reuters) - Britain's King Charles yesterday cancelled a state visit to France after social unrest over President Emmanuel Macron's new pension law erupted into some of the worst street violence seen in years across the country.

The postponement will be a major embarrassment to Macron, who had hoped the monarch's visit would mark a symbolic step in the two countries' efforts to turn a page after years of poor relations postBrexit.

Charles had been due to travel to France on Sunday for three days before moving on to Germany, an itinerary that had been seen as a win for the French leader who has sought to position himself as Europe's de facto leader.

The king's visit had been due to include a lavish banquet at the Palace of Versailles and the postponement will pile further pressure on Macron to find a way out of a crisis over his plans to raise the retirement age, which has seen some of France's worst unrest since the "Yellow Vest" rebellion of 2018-2019.

"The King and The Queen Consort's State Visit to France has been postponed. Their Majesties greatly look forward to the opportunity to visit France as soon as dates can be found," a Buckingham Palace spokesperson said.