Thousands of workers have rallied across France against the government’s plan to raise the retirement age to 64.
Union activists cut electricity to nearly 100,000 homes or offices in Bordeaux and Lyon, while staff at the Eiffel Tower walked off the job.
Even Paris opera workers joined in Tuesday’s nationwide protests, singing an aria of anger.
Despite 13 days of crippling train and subway strikes, French president Emmanuel Macron and his government stayed firm.
Prime minister Edouard Philippe declared his “total” determination to reshape a pension system which unions celebrate as a model for the rest of the world, but which he calls unfair and destined to collapse into debt.
Lighting red flares and marching beneath a blanket of union flags, thousands of workers snaked through French cities from Brittany on the Atlantic to the Pyrenees in the south.
Hospital workers in scrubs, Air France staff in uniforms and lawyers wearing long black robes joined people from across the French workforce in the strikes and protests in higher numbers than the last cross-sector walkout last week.
The retirement reform is just one of their many gripes against Mr Macron, a business-friendly centrist they fear is dismantling France’s costly but envied welfare state.
Workers from the hard-left CGT union carried out what they called “targeted” blackouts on electricity networks around Lyon and Bordeaux to call attention to their grievances – and their power.
Several European countries have raised the retirement age or cut pensions in recent years to keep up with lengthening life expectancy and slowing economic growth. Mr Macron argues that France needs to do the same.
Tourists cancelled plans and Paris commuters took hours to get to work on Tuesday, as train drivers kept up their strike against changes to a system that allows them and other workers to retire as early as their 50s under special pension regimes.
The Eiffel Tower was shut for the second time since the strike – one of the most protracted France has seen in years – started on December 5.
Police in Paris barricaded the presidential Elysee Palace, bracing for violence by yellow vest activists or other radical demonstrators.
Across the French capital, union leaders said Mr Macron should drop the retirement reform.
“They should open their eyes,” said Philippe Martinez, the head of the CGT union, at the head of the Paris march.
With riot police watching closely, protesters carrying humorous signs and colourful costumes marched past the historic Bastille plaza. On the steps of the opera house overlooking the monument, workers sang famous arias and played instruments to defend their special retirement plan.
Bernard Buffet, a costume fitter, is 63 and retiring in April after 35 years at the Bastille Opera, but is protesting in solidarity with younger colleagues.
“The government is stuck on the reform. They are very arrogant,” he said.
Mr Philippe confirmed new negotiations with unions will start on Wednesday, but showed no sign of backing down.
“Democratic opposition, union opposition is perfectly legitimate,” he told MPs. “But we clearly laid out our plans. And on this plan, the creation of a universal retirement system, my determination … is total.”