France braces for 'mass disobedience' protests

French unions and student groups are set to take to the streets for another day of protests on Saturday, while the Yellow Vests movement plans a separate rally in central Paris despite a ban by authorities.

The demonstrations follow weeks of youth-led unrest and nationwide strikes that drew hundreds of thousands of workers protesting over the rising cost of living.

They come less than six months before voters elect a new head of state to replace centrist President Emmanuel Macron, with the far right leading in the opinion polls.

Student groups and trade unions have called for an authorised march in central Paris "against the high cost of living and in support of young people".

Yellow Vests activists, however, have refused to join, instead calling for a separate rally at Place de la Concorde, near the lower house of parliament and presidential palace, despite a ban by authorities.

Interior Minister Laurent Nunez said 70,000 police officers and security forces would be deployed across the country.

"If there are any rioters or looters... we'll be ready and waiting for them," he said.

The demonstrations have been largely peaceful, but there have at times been clashes with police or vandalism on their sidelines, including on October 17, when France saw its worst rioting in years.

On Thursday, hundreds of thousands of striking workers took to the streets across France in mostly orderly protests, although clashes between demonstrators and police broke out in several cities.

The Yellow Vests movement, which staged street protests eight years ago against Macron's government over planned fuel-tax hikes, has called for its banned rally to go ahead.

"We are calling for mass disobedience," said Benjamin Ball, a member of its coordinating committee.

Authorities are determined to prevent a repeat of the rioting and looting that marred the October 17 demonstrations, although the interior ministry said Thursday's protests had "generally gone well" despite 642 arrests.

The police response has faced criticism for being heavy-handed, with dozens of internal investigations launched into allegations of brutality against demonstrators.

Prime Minister Sebastien Lecornu has said he will discuss wages and purchasing power with representatives of trade unions and employers' organisations on Monday.

"The only thing that will bring the protests to an end is a response to the demands that have been put forward for several weeks by workers, civil servants, young people and pensioners," an inter-union coalition said on Friday.

The unions are calling for an increase in the minimum wage, which has not received any discretionary boost since 2012, across-the-board wage raises, tax reforms and better learning conditions for young people.

With the European Union's second-largest economy under pressure to rein in debt, the government has limited scope to appease protesters.