Huge crowds marched across France to say "non" to President Emmanuel Macron's plan to make people work longer before retirement, with pressure in the streets intensifying against a government that says it will stand its ground.

Opinion polls show a substantial majority of the French oppose increasing the retirement age to 64 from 62, a move Mr Macron says is "vital" to ensuring the viability of the pension system.

The French Interior ministry said that a total of 1.272 million people took part in the protests nationwide, up slightly from the first nationwide demonstration on 19 January. In Paris, a total of 87,000 people marched, compared to 80,000 on the same date, it added.

"It's better than on the 19th. ... It's a real message sent to the government, saying we don't want the 64 years," Laurent Berger, who leads CFDT, France's largest union, said ahead of the Paris march.

Union leaders at a joint news conference at the end of the march said they would organise more strikes and demonstrations against the reform on 7 and 11 February.

Marching behind banners reading "No to the reform" or "We won't give up," many said they would take to the streets as often as needed for the government to back down.

"For the president, it's easy. He sits in a chair ... he can work until he's 70, even," said one protester in Saint-Nazaire. "We can't ask roof layers to work until 64, it's not possible."

Striking workers disrupted French refinery deliveries, public transport and schools, even if, in several sectors, fewer walked off the job today than on 19 January as a cost-of-living crisis makes it harder to skip a day's pay.

Gare De Lyon Paris
Travellers wait at a fare gate during delays at Gare de Lyon station in Paris today

For unions, the challenge will be maintaining walkouts at a time when high inflation is eroding salaries.

A union source said some 36.5% of SNCF rail operator workers were on strike by midday - down nearly 10% from 19 January - even if disruption to train traffic was largely similar.

On the rail networks, only one in three high-speed TGV trains were operating and even fewer local and regional trains. Services on the Paris metro were thrown into disarray.

Utility group EDF said 40.3% of workers were on strike, down from 44.5%. The education ministry also said fewer teachers walked off their job.

Unions and companies at times disagreed on whether this strike was more or less successful than the previous one. For TotalEnergies, fewer workers at its refineries had downed tools, but the CGT said there were more.

In any case, French power supply was down by about 5% or 3.3 gigawatts (GW) as workers at nuclear reactors and thermal plants joined the strike, EDF data showed.

And TotalEnergies said deliveries of petroleum products from its French sites had been halted, but customers' needs were met.

The government has said that pushing the retirement age to 64 is "non-negotiable".

And with the reform posing a test of Mr Macron's ability to push through change now that he has lost his working majority in parliament, some felt resigned amid bargaining with conservative opponents who are quite open to pension reform.

The pension system reform would yield an additional €17.7 billion in annual pension contributions, according to Labour Ministry estimates. Unions say there are other ways to raise revenue, such as taxing the super-rich or asking employers or well-off pensioners to contribute more.

"This reform is unfair and brutal," said Luc Farre, the secretary general of the civil servants' UNSA union.

At a local level, some announced "Robin Hood" operations unauthorised by the government. In the southwestern Lot-et-Garonne area, the local CGT trade union branch cut power to several speed cameras and disabled smart power meters.

"When there is such a massive opposition, it would be dangerous for the government not to listen," said Mylene Jacquot, secretary general of CFDT's civil servants branch.