Emmanuel Macron's presidency 'on the line' as France braces for crippling 'Black Thursday' of pension strikes

France faces paralysis on Thursday as it braces for one of the  biggest nationwide strikes in years in a tense standoff between President Emmanuel Macron and unions that police fear could turn violent.

In what has already been dubbed “Black Thursday,” hundreds of domestic and short-haul international flights have been cancelled.

EasyJet has axed 223 flights and warned others risk being delayed while delays and cancellations are expected on cross-Channel Eurostar rail services. Ninety per cent of France’s fast TGV and regional trains will not be running.

Most of the Paris metro will be shut along with the majority of schools in a major showdown over Mr Macron’s planned pension reforms and which unions warn is “open-ended” and could last for days.

French commuters are preparing alternative modes of transport from bikes to e-scooters and car-sharing amid comparisons with a homeric clash over pensions in the winter of 1995, which saw the country paralysed for three weeks. The Chirac administration eventually caved in.

The standoff is seen as a key litmus test of Mr Macron’s reformist mettle.

Early in his presidency, he rushed through labour and public rail reforms but then lost steam over the “yellow vest” revolt. Isolated on the international stage over Nato, domestic defeat could turn him into a lame duck.

"Pensions is the big test. If we stall, the presidency is over. We won't do anything else", one government heavyweight is cited as warning in Le Monde.

Unions, meanwhile, are keen to show they still command clout after their failure to strong-arm Mr Macron into backtracking earlier reforms and being sidelined during the gilets jaunes protests.

This time, an array of mainly public sector workers will down tools with hundreds of thousands of rail, bus, airline and utility staff, along with nurses, teachers, civil servants and police expected to turn out. Fuel depots may be blocked.

Mr Macron insists that now is the time to end unfair discrepancies between 42 different “special”  regimes that allow some to retire on a full pension in their early fifties. He wants a single points-based system in which each day worked earns points for a worker’s future pension benefits.

Currently pension benefits are based on a worker’s 25 highest earning years in the private sector and the last six months in the public sector.

At 14 per cent of economic output, French spending on public pensions is among the highest in the world. The system will run a deficit of more than €17 billion by 2025 if nothing is done, independent experts warn.

Most unions have already rejected the reform, even though it has shied away from raising the official retirement age - currently 62 - and will not be unveiled in detail until next week.

Thomas Piketty, the Left-wing French economist, said it claimed to be “universal” but in fact disadvantaged the poor, whose life expectancy was several years shorter than the rich. Top earners would end up paying less into the pay-as-you-go system, he claimed.

The French are paradoxically split, with a majority expressing sympathy for strikers and an almost equal number agreeing the government should see the reform through.

Government talk of sweeteners for teachers and “room for manoeuvre” with public transport workers appear to have had little effect.

“Turnout out will be high. The real question is will there be violence?,” said one Macron aide.

Security services fear that yellow vests, whose weekly protests ended in sometimes extreme violence in Paris and other cities, could return to the fray along with a hard core of “black bloc” anarchists.

Christophe Castaner, the interior minister, said that 245 demonstrations were expected nationwide, warning that a radical fringe of demonstrators could cause trouble.

"We know there will be lots of people in these protests and we know the risks. I have requested that systematically when there is rioting or violence we make arrests immediately," he said.

“Social movements are becoming more unpredictable and more violent,” one minister told Le Monde, which cited another top official as saying Paris’ police chief was “worried”.

“The big concern is that the unions won’t be able to control the thing.”

“There is a clear radicalisation of French society,” said one source close to the prime minister. “We have moved from an acute crisis phase to a chronic crisis phase.”

Danielle Tartakowsky, a historian of social movements, said: “You’d think we were on the eve of a typhoon. I don’t remember ever having experienced this."

“We have entered extremely turbulent waters,” she told Le Monde.