The Socialists are set to wrest back the Elysee Palace from the Right after a gap of 17 years in Sunday's presidential poll.
Francois Hollande has maintained a consistent and comfortable lead over Nicolas Sarkozy in opinion polls and the incumbent's increasingly desperate swing to the far right appears to have failed to shore up sagging support. A poll on Thursday gave Hollande 53.5 per cent against 46.5 per cent for Sarkozy.
In the first round of the presidential election on April 22, 1.8 million French voters who had backed Sarkozy last time turned their backs on him.
They vented their anger at his embrace of austerity and the misery this has brought to the majority in a country hit by 9.8 per cent unemployment, spreading poverty and cuts to public services and welfare.
They are also unforgiving of Sarkozy's love-in with German Chancellor Angela Merkel, with whom he dreamed up the Fiscal Compact, an austerity death grip that was agreed in March by EU governments.
In contrast to Sarkozy, whose policies reflect his close ties with the country's rich and business elite, Hollande, who gained an additional 770,000 votes in the first round compared with the previous Socialist candidate Segolene Royale, would represent a big improvement.
Hollande is less friendly to the rich, pledging a 75 per cent tax on incomes of over €1 million a year, and the banks, demanding a split between retail and investment businesses in a move that should curb speculation while protecting people's savings.
And he's better on public services. Against Sarkozy's record of pay freezes and spending curbs, he's committed to hiring 60,000 teachers for the country's overstretched schools.
Furthermore he advocates the issuing of euro bonds guaranteed by the 17 countries using the common currency to raise funding for debt-strapped countries, which Sarkozy, like Chancellor Merkel, opposes.
And Hollande wants the "Merkozy" Fiscal Compact "renegotiated" and rejects the linked "golden rule" to balance budgets that Sarkozy has pledged to insert in the French constitution.
This would reduce an economy that was once the proud champion of state-led "dirigisme" and planning into a Thatcher-style corner shop business.
But at the same time the Socialist leader has pledged to balance the budget by 2017, one year after Sarkozy plans to.
This means that while he's mounting an important defence of the sovereign right of France's parliament to set a budget and decide how much it taxes and spends in principle, in practice there's little difference between him and Sarkozy on austerity policies.
By committing to impose such a deathly fiscal straitjacket, and with no serious plan to tackle the power of finance, he's tying his hands over any serious programme to kick-start the French economy and tackle deep-rooted problems of inequality of wealth and power.
This will make the role of the Left Front on the Socialists' left flank crucial.
In the first round this new force, formed in 2008 from the Communist Party and left radicals including former Socialists like presidential candidate Jean-Luc Melenchon, achieved a historically significant result with 11 per cent of the vote.
It fell short of some polls predicting up to 17 per cent, that's true. But the final count was nevertheless impressive.
In 2007 the collective vote for the radical left - comprising the New Anti Capitalist Party's Besancenot, the Workers' Struggle's Laguiller, the Workers' Party's Schivardi and the Communist Party's Buffet - was 3.3 million. This time it was 4.6 million, or a rise of 39 per cent.
And the spread of votes was impressive.
The party gained at least 7 per cent of the vote in all 96 French départements (the unit of government above communes but below regions) on the mainland (ie excluding the overseas territories) with more than 10 per cent in 76 of départements and over 13 per cent in 20 of them.
Furthermore, a number of large cities without any communist tradition, like Grenoble, Lille, Montpellier and Toulouse, gave the Left Front a score of over 15 per cent.
Most importantly, it was the Left Front's electoral boost that lifted the overall left score - including the Socialists - to 15.7 million votes, a rise of 17 per cent.
In short it was the Left Front with its call for a "citizen's revolution" that will, assuming all the polling is correct, have propelled Hollande to head of state.
As Melenchon puts it, the Left Front is the real dynamic force on the left.
The personal performance of the former Socialist minister, his language that fuses the best of French revolutionary and republican tradition, his brilliance both at large rallies and on TV, are all part of the success story. But clearly so is the Left Front's programme.
For sure, it is not a revolutionary set of policies. But it fills the political space that social democrats vacated long ago. Some have called it "radical reformism."
His programme calls for:
A 100 per cent tax on earnings over €297,000 a year
Full pensions for all from the age of 60
Reduction of work hours
A 20 per cent increase in the minimum wage
The nationalisation of energy companies
The creation of a well resourced public investment bank
A demand for the European Central Bank to lend to European governments at 1 per cent, as it does for the banks
A categorical "No!" to the Fiscal Compact
A referendum with recommendation to withdraw from the EU's Lisbon Treaty.
And running through Melenchon's bid to remake France is a determination to end the chaos and environmental and social destruction of uncontrolled free markets and replace it with what he calls "ecological planning."
Above all, as the Humans First! title of the programme says, it aims to restore people to the centre of a new Sixth French Republic.
The rise and rise of this new force on the left is part of a wider radicalisation of the French electorate, however.
On the right this produced a shocking 18 per cent vote for the anti-immigrant, anti-EU Marine Le Pen.
This beats her father's historic 16.9 per cent score of 2002. That saw him overtake the Socialists and stand in the run-off election with traditional right winger Jacques Chirac, who defeated the far-right candidate.
Once a party for the petit-bourgeoisie, the racist Front National is now solidly embedded in the working class.
One extensive poll found Marine Le Pen was backed by 35 per cent of workers, with a 29 per cent rating among the less educated workers.
In this election Le Pen junior maintained the Front National's strong position in the Mediterranean coast, first conquered by her father in the 1980s, and did well in the north-east of France and other places, where industry has suffered dramatic neglect and decline.
She also picked up votes from working-class people who have been forced out of the cities because of escalating urban rents and house prices, and whose physical displacement has clearly been matched by a political and cultural displacement taking them out of the orbit of traditional parties of the left and right.
There's a danger in misreading Le Pen's score. In 2007 the votes for Le Pen senior and another far-right candidate - Bruno Megret, a former leading figure in the Front National - polled 19 per cent between them.
What's happened is that former Sarkozy voters among the working class have migrated right, thanks not only to their disillusionment with his five-year reign but also to his headlong lurch to the far right himself, with attacks on immigrants and latterly the adoption of the even more corrosive language of Petain, the collaborationist war-time leader.
Melenchon's own analysis is that this has been a "transfusion" of right-wing voters further right, with examples being Lyon, Lille, Marseille and the town of Florange in Lorraine where a steelworks is under threat.
If the Front National has made further inroads into the working class, there were places where the Left Front's and the Front National's head-to-head clashes ended up with the Left Front coming out best. In Marseille, while Sakozy lost 30,000 votes, Le Pen won 28,000 and the Left Front, after delivering a strong anti-racist message, gained 42,000 votes (compared with a net gain of just 1,000 for the Socialists).
The message for Melenchon and his supporters is that without the Left Front and its progressive and unashamedly pro-working class message, the far right would have done much better.
Nevertheless the Front National is a major threat. The result has emboldened Le Pen to make a bid for leadership of the right, a move that was underlined by her call to supporters to not only reject Hollande on Sunday but Sarkozy too.
If, as both Le Pen and many commentators predict, Sarkozy's UMP party is heading for meltdown - with the more moderate wing alienated by its chief's embrace of her nasty politics of hate and the right opting for the real thing - she has a historic opportunity to revamp the reactionary political camp into an Italian-style populist neo-fascist movement.
The defeat of Sarkozy is all but inevitable now.
But this radicalisation of French politics will be tested again in June's parliamentary elections.
The Left Front is hoping to maintain its momentum. And while asserting its clear independence from the Socialists, it is currently discussing with them a pact to back the most promising candidate in constituencies where there is a risk of the left not making it through to the second round of voting.
Historically the odds are on trends in presidential elections to follow through in parliamentary elections. So a left president and a left parliament beckon.
But for it to make a real difference both to the French people and Europe as a whole it will need to embrace the spirit of rebellion of Melenchon's "citizen's revolution."