The protest movement against the pension reform has turned into the biggest domestic crisis of Macron's second mandate, with police and protesters clashing daily in Paris and other cities over the past week.

As well as an embarrassment to French President Emmanuel Macron, the postponement is a disappointment for Charles, taking the gloss off his first international engagement since succeeding his mother Queen Elizabeth in September.

Almost 150 police were injured and scores of protesters arrested nationwide, as a day of protests descended into chaos in several cities including Paris, where protesters lit fires in the historic centre of the city.

A survey shows Macron's personal approval rating at just 28%, its lowest level since the height of the anti-government 'Yellow Vest' protest movement in 2018-2019.

The outcome prompted immediate anti-government protests, with 101 people arrested in Paris alone in tense standoffs between protesters and security forces.

The government's decision last week to resort to Article 49.3 of the constitution to force the bill through parliament without a vote has prompted anger in the streets after weeks of mostly peaceful protests.

The president has made no public comments since the bill to raise the retirement age from 62 to 64 was forced through.

Across France, fresh protests have erupted, the latest show of widespread opposition to the bill since mid-January.

The move to use a special constitutional power enabling the government to pass legislation without a vote amounted to an admission that it lacked a majority to hike the retirement age from 62 to 64.

Support appears almost certain in the upper house Senate, but a majority will be more difficult to find in the fractured assembly.

Mohamad Hasan says efforts are being made to trace those involved.

Police reportedly expect between 1.1 million and 1.4 million people to hit the streets.