Stand by for the dirtiest French poll for decades

The President enters the fray, and immediately the insults fly

Put on your tin chapeaux. This is going to be the nastiest electoral campaign in recent French political history. In three days of frantic campaigning since he finally entered the race, President Nicolas Sarkozy has called the Socialist front-runner, François Hollande", a "liar, both morning and night", part of an "immobile elite" and a member of an arrogant "caste" that opposes the real interests of the French nation.

Mr Hollande, holding a substantial but narrowing lead in the polls nine weeks before the first round of voting on Sunday 22 April – there will be a second round on 6 May for the two leaders – already looks a little shell-shocked. He has countered by accusing Mr Sarkozy of "falsification", "manipulation", "brutality and wickedness". The Socialist candidate appealed on Friday for a "dignified" election campaign. Some hope.

New, and worse, vituperation can be expected when the President holds the first mass meeting of his re-election attempt before flag-waving centre-right supporters in Marseille this afternoon.

You have to hand it to Mr Sarkozy. As the most unpopular president in recent French history, he plans to fight an unashamedly populist campaign. From his guerrilla base inside the Elysée Palace, he plans to run as an outsider or, in his own phrase, "an ordinary Frenchman among the French".

A man widely seen as having governed on behalf of a small tribe of his rich friends has cast himself as the candidate "of the people" fighting a "statist and corporatist elite". A president who has sworn to defend "French values" and "French national identity" has modelled his campaign on the tar-brush politics of the American right.

Mr Hollande will be painted relentlessly in the next couple of weeks as "immobile", "mendacious" and the representative of "powerful interests and castes who oppose all change". President Sarkozy will, equally energetically, push hot-button, right-wing "value" issues such as family, discipline, work and identity.

His Interior Minister, Claude Guéant, a long-time Sarkozy ally, has angered the President's more moderate senior supporters by saying that "some civilisations are worth more than others" and must be defended. If you read French and care to trawl the web, you will find that this is the language of the furthest right in France, the hardliners who oppose the allegedly moderate drift of the new National Front leader, Marine Le Pen.

Mr Sarkozy has the highest negative ratings of any French leader approaching an election in recent times. Judging by conversations in recent days with ordinary citizens and political activists in Alsace, Burgundy and Paris, the hostility to him is not simply political; it has been deepened by, but pre-dates, the economic crisis.

The objection to Mr Sarkozy is personal. It is a gut thing. "There is something about his personality that many people can no longer stomach," said a centre-right politician in Burgundy, who campaigned for the President in 2007. "People think that he has demeaned the office by, for instance, shouting insults at bystanders who insulted him. Or by pushing his 22-year-old son forward for a senior political post. He promised in 2007 that his presidency would be all about them. They have the impression it has been all about him: his divorce, his celebrity courtship, his celebrity marriage, his son."

Laurent, 24, a student in Strasbourg, a centre-right voter thinking of moving to the far right, said: "With Sarkozy, everything has been frantic gesticulation but no progress – lots of noise but little action. I think people are exhausted by him."

This is a frequent complaint. President Sarkozy's answer is, it appears, a noisy, frantic and divisive campaign. Can it work?

After flat-lining for weeks, opinion polls have flickered towards him since he declared his candidature on Wednesday. A BVA poll on Friday put Mr Hollande's support at 31 per cent for the first round and Mr Sarkozy at 26 per cent. The far-right Ms Le Pen and the centrist François Bayrou have fallen back, for now, leaving a two-horse race towards the two berths in the second round two weeks later.

When it comes to a Hollande-Sarkozy run-off, the polls remain terrifying for the President. The BVA poll puts Mr Hollande's second round support at 56 per cent and Mr Sarkozy's at 44 per cent. No sitting president in the Fifth Republic (since 1958) has ever had such bad figures at this stage. Even President Valéry Giscard d'Estaing, the only one who went on to lose, polled better against the eventual winner, François Mitterrand, in 1981.

No mainstream candidate of any kind, president or challenger, centre- left or centre-right, has fought back from such poor February figures to win. In every election since 1979, the electorate has, one way or another, rejected its previous choice. Hence, in part, Mr Sarkozy's brazen decision to run as an incumbent outsider. The President's calculation is that Mr Hollande is a straw man, that there is no real enthusiasm for him, that the Socialist candidate's popularity is a mirror-image of the ambient Sarkophobia, which can be effaced.

Mr Hollande is running a tortoise-against-hare campaign. In conversation with British and US media correspondents over lunch last week, the front-runner was charming, funny, approachable, eloquent and knowledgeable. He came close to admitting that his moderate, safe-pair-of-hands, "normal" candidature would perhaps not work in any other year; or against any other candidate. "I decided to run," he said, "because I felt that, at this time, and perhaps no other, I happen to offer the blend of qualities which... the electorate is seeking and would allow [France] to succeed: stability, serenity, respect, restraint."

But in trying to be all things to all men, Mr Hollande may end up annoying both the further left and the centrist voters that he needs. In his conversation with the "Presse Anglo-Saxonne", he moderated his earlier pledge that he would make the world of finance his enemy.

He said he wanted sensible reforms that would curb the worst excesses of the banks and the hedge funds, but that the City of London need not fear him unduly. Past Socialist governments had, in fact, "liberalised" aspects of the French economy, he pointed out. There were "no more Communists in France – or very few".

Much of this is a statement of good sense and the obvious. In the inflammable, pre-electoral mood, it infuriated the hard left and gave a sound-bite opportunity to the right. President Sarkozy accused Mr Hollande of "saying one thing to the French and another thing to the British". He was, therefore, a liar.

There will be more of that kind of thing in the next few days. Much more. Mr Sarkozy's campaign team knows that time is short. French electoral intentions tend to solidify in late February or early March. The hare has to catch up with the tortoise in the next fortnight. Otherwise, he is cooked.