By Emma-Jane Kirby
BBC News, Paris
The strikes are happening in towns and cities across the country
Last summer, President Nicolas Sarkozy boasted that these days when there is a strike in France, nobody notices.
But this time, with three-quarters of French people and all the main unions backing the walk-out, the strike will hit hard.
In Paris, train and underground services are disrupted and up to a third of Air France short-haul flights will be cancelled. Many schools and post offices are shut, with courts, hospitals and power companies also affected.
Demonstrators are taking a hotchpotch of grievances to the streets, from cut-backs in education to new judicial reforms they worry will threaten the independence of the French justice system.
But the strikers are united by one common fear - that France's economic climate is worsening and that the government is responding inadequately to the crisis.
Many are angry that the banks were given a multi-billion euro bail-out while floundering industries and businesses were offered far less help.
A few months before the credit crunch struck, Mr Sarkozy snapped at grumbling journalists, who were complaining about low wages and poor spending power, that there was no money left in the till for handouts.
So where, the French people are now asking, did the 360bn euro shore-up fund to guarantee banks come from? This, at a time when the government was busy slashing thousands of public sector jobs, trimming pension benefits and planning massive cuts to the education budget.
And why, despite receiving such a generous support plan, are the French banks still refusing to pass on loans to desperate businesses - especially when many of those banks have announced sizeable profits this year?
Unions argue that the government's stimulus package should focus less on companies and more on workers' job protection and purchasing power.
Nicolas Sarkozy has shelved some unpopular cost-cutting reforms
There is a general feeling here of injustice, that the ordinary man on the street is paying for the greed of those in the financial sector.
With strikes called in nearly 80 different towns and cities across the country and demonstrations planned in some 200 towns, this day of action looks like being the biggest one-day strike since Mr Sarkozy took office in May 2007.
No-one expects the government to solve the credit crunch, but they do hope that a mass turn-out on the streets will make the government realise they will not be railroaded by a programme of cuts and reforms - and are still a force to be reckoned with.
Unemployment looks likely to hit 10% here by next year, and the French people are now looking for assurances from their president that he will drop his programme of cost-cutting reforms and instead turn his attention to re-launching the ailing economy.
The French leader insists he will stick to his plans, but he has already shelved some unpopular plans to slash 13,500 jobs in the education sector.
This, after all, is a country where street protests have repeatedly brought down political leaders and Mr Sarkozy does not want his own name added to that list of casualties.