Is French President Nicolas Sarkozy on the verge of a record comeback?

He still trails Socialist challenger Francois Hollande, but in just three months of intense campaigning he has dragged himself back in the race for the presidency.

When French voters go to the polls on April 22 for the first round of the presidential election, the right-wing incumbent is all but certain to win a place in the run-off against front-leader Hollande on May 6.

As recently as the New Year, Sarkozy was languishing with the lowest approval ratings in modern French history. He was not even sure of surviving the cut in the first round and faced defeat by 60 percent to 40 if he made the run-off.

Now with less than two weeks to go, borne along by events and an aggressive campaign, he can legitimately hope to come on top in the first round and to mount a credible challenge to Hollande in the second.

"I can feel the wave building," he declared, a quotation that served as the front page headline of the French weekly Le Journal du Dimanche, next to a beaming picture of the reborn 57-year-old candidate.

His time in the doldrums seems not to have knocked the arrogance out of him. "I'm going to win and I'll tell you why. He's no good and people are starting to see it. Hollande is useless," he told Le Monde last week.

The Socialist, also 57, tried to rise above the "playground" insult, another example of the pair's wildly different styles. Hollande is affable rather than provocative, even promising to be a "normal president."

Sarkozy's response to Hollande's long period of dominance in the polls was unexpected. Rather than try to recapture the centre ground that entrusted him with office in 2007, Sarkozy tacked sharply to the right.

"We have too many foreigners in France," he declared, bringing his rhetoric on immigration, restoring European border controls, expelling extremist Muslims and on trade protectionism closer to that of Marine Le Pen's far-right.

Hollande might have countered by sticking to the themes of job security, household spending power and an end to EU-mandated austerity spending -- on which he is stronger -- but events brutally intervened.

A killing spree in southern France by a self-declared Al-Qaeda militant turned the national debate back to security issues, and Sarkozy capitalised on a subsequent highly-publicised wave of arrests in Islamist circles.

Hollande, by nature a less agitated performer, has remained unruffled as his poll lead has begun to erode. During the aftermath of the shootings he acted as a shadow president, attending ceremonies as a supporting player.

With the French electorate shaken by the recent economic crisis and tired of Sarkozy's showboating, it seemed Hollande's quietly confident rise would be enough to win the left its first presidential election in a quarter century.

But Hollande, while a long-standing backroom player in the Socialist Party and a good television performer, had no large constituency outside the party and no previous ministerial experience.

For many he was a second choice candidate after charismatic former finance minister and IMF chief Dominique Strauss-Kahn saw his high-flying career destroyed last year by a series of allegations of sexual misconduct.

Most polls now predict Sarkozy to win around 30 percent of the vote in the first round with Hollande coming second with between 26 and 29 percent of the vote. Hollande is still on course to win round two, but now only by 55 to 53 percent of the vote.

And the second round, by necessity hypothetical, is harder for pollsters to predict. The surviving pair will have two weeks to debate head-to-head and try to win over the disappointed supporters of their lesser rivals.

In the run up to the first round, Hollande has been outflanked on the left by Jean-Luc Melenchon, a former Socialist minister turned leftist firebrand who has edged into third place with a nostalgic appeal to revolutionary values.

Openly disdainful of Hollande's cautious economic orthodoxy -- Sarkozy aims to reduce the deficit to zero by 2016, Hollande by 2017, both through a mix of cuts and tax rises -- Melenchon might win 15 percent in the first round.

The Socialist candidate has been vague about where cuts would come, but has promised higher taxes on the wealthy. Sarkozy insists on the need, in a Europe hobbled by debt, to cut deep into the public sector.

Hollande hopes the hard left will begrudgingly swing behind him as a better option than Sarkozy in the second round, just as Sarkozy hopes that he has sent strong enough anti-immigration signals to tap Le Pen's right-wing electorate.

This leaves the centre high and dry. Francois Bayrou, of the centre-right MoDem party is one of the most popular politicians in France, to judge by approval rating polls, but his campaign has gone nowhere.