Sarkozy shows no sign of relenting, and with thugs attaching themselves to the fringes of demonstrations, there is fear on both sides about where the crisis is headed.
French unions plot next move in pension reform crisis
With much of the world looking on in bewilderment, France remains in turmoil amid its most disruptive wave of strikes, blockades and street protests in 15 years.
Unions, students and other demonstrators protesting against Nicolas Sarkozy's proposed pension reforms have closed about a third of the country's petrol stations, paralysing everyday life in many areas.
Numerous flights and trains have been cancelled and port blockades in the second city of Marseille have prevented a fleet of tankers from delivering oil to refineries.
Serious outbreaks of lawlessness are adding to the impact of the industrial action. Rioters have set fire to cars and schools, looted shops and clashed with police, confronting the country with its worst civil unrest since violent disturbances spread from the immigrant-dominated suburbs of Paris to most cities and towns in 2005.
It is the combination of widespread strikes and rioting that makes the present crisis deeper than any since 1995, when the then prime minister Alain Juppe was forced to abandon his attempt to reform the pension system.
Although the upper house of the French parliament may pass Mr Sarkozy's plan as early as today after the government moved yesterday to accelerate its passage through the Senate, unions and students are already considering how to continue their action into next week.
With masked young thugs of no obvious political alignment on the fringes of demonstrations, there is fear on both sides about where the crisis is leading.
The president says he will not back down, describing the reforms, which would raise the minimum age of retirement from 60 to 62, and the age for entitlement to full pensions from 65 to 67, as "neither left nor right wing but good sense". Pension deficits have reached €32 billion (Dh164bn) a year, a level he insists the country cannot sustain.
Mr Sarkozy has ordered police to clear blockades of fuel depots and knows he would forfeit credibility internationally, and among his centre-right voters, if he succumbed to street power.
But comparisons with the spring revolt of 1968, when workers and students seemed on the point of bringing down the government, are now commonplace, dominating television and radio discussion programmes only a few weeks after being dismissed as exaggerated.
The stakes are high even if the immediate cause of the discontent seems, to many outsiders, relatively trivial. In most other countries, where people are already accustomed to working until 65 and will have to wait even longer for retirement in future, the bid to overhaul the system to take account of greater longevity appears to fall far short of revolutionary.
However the French, cushioned by a generous welfare state that has produced a much-envied health service and strong protection for employees as well as comfortable pensions, are in no mood to give up what they see as hard-won benefits.
Mr Sarkozy was elected on a platform of reform, but has shared the fate of presidential predecessors – popular resistance – when trying to implement his programme.
No one is surprised that recent opinion polls show 70 per cent of the country in support of the strikes and his own rating as its lowest since he took office.
Mr Sarkozy may be counting on public opinion turning against the strikers. But Bernard Thibault, leader of the powerful CGT union, called in a radio interview yesterday for a new round of protests.
"The government remains intransigent," he said. "We need to continue with massive action."
Jerome Sainte-Marie, the head of political research for the CSA polling institute, says both the government and the unions are losing control, with even the socialist opposition apprehensive "because they could be largely discredited if there are excesses".
He told the business magazine L'Expansion that popular support for strikes had peaked and may now fall with opinion swayed by fuel shortages, roadblocks and, above all, images of violence by youths beyond union control.
Yet some analysts attach most blame to Mr Sarkozy and say he will emerge severely weakened even if his gains ground.
Jacques Reland, head of European research at the left-leaning Global Policy Institute, said: "Although it is surprising to see certain groups – refinery and rail workers who would not suffer too much from pension reform – acting so strongly, they see what is happening as the thin end of the wedge. They feel that to give in on this would hand a blank cheque to the government to dismantle France's welfare state."
Mr Reland feels that even if Mr Sarkozy wins this battle, he will have alienated so many people with his style of government that he would stand little chance of winning a second presidential term.