He will be the youngest man to occupy the Elysee Palace for 29 years. He will be the first French leader to be born after the Second World War. And at 5ft 5ins, he will be, by far, the shortest man to be president during the Fifth Republic.

Sarkozy has run a deeply unpleasant campaign, in the name of some sensible ideas and some disturbing ones. He has promised to unite France, but has successfully appealed to the more tribal instincts of the hard right and the white middle classes. After the muddled era of Le Roi Chirac, and the glittering, then tarnished, era of Le Roi Mitterrand, the world will have to learn live with Le Roi Sarkozy. It is unlikely to be an easy ride for the French or anyone else.

Nicolas Sarkozy, 52, is accused by his many enemies in France . . .

not all of them on the left . . . of being too American or too "AngloSaxon" in his attitudes, but the world is likely to find that the president-elect is deeply French.

His ambition is to be a new Charles de Gaulle, someone who rebuilds the self-esteem and economic strength and international influence of France. He favours lower taxes and a more liberal labour market, but believes in the interventionist duty of the state.

Sarkozy has achieved the extraordinary coup . . . or imposture . . . of winning by running against the record in government of his own centre-right party. He will almost certainly win the "third round" of the elections, the parliamentary poll, which follows next month. Then his problems will begin.

The more militant, and even some moderate, French trade unions are spoiling for a "fourth round", in which they will oppose the new president's allegedly "ultra-capitalist" social and economic reforms in the streets next autumn. Demonisation of Sarkozy in the poor, multi-racial suburbs of French cities has reached such a pitch that the new President might also face an incendiary "fifth round" . . . a rekindling of the riots of autumn 2005.

New protests The slightest incidence of police violence after Sarkozy takes office could trigger new protests. The French police, who regard him as "their man", are unlikely to be in an accommodating mood when the hyper-active former interior minister occupies the Elysee Palace. The Socialist candidate, Segolene Royal, has issued a series of undignified warnings in recent days that a Sarkozy presidency might "unleash a wave of violence and brutality across the country". She was wrong to say it . . . but she was not the only person to fear it.

Royal ran a frustrating, muddled campaign, which finally came alive in the last few days. In a series of eloquent, passionate speeches around the country, she begged the French people to choose her "creative energy" over the "negative energy" of her opponent. She also gave a gutsy and fluent performance in a televised debate on Wednesday, but it was already too late. The nation was watching Sarkozy, and by attacking him so vigorously, Royal ended up doing him a favour. Would he become nasty under pressure?

He did not.

Sarkozy's debate persona . . . reasonable, restrained . . . was utterly different from the angry, fingerjabbing little man who has been roaming the country for the last four months. At his rallies, he appealed to the tribal . . . and, some say, racial - instincts of the right and hard right. He posed as the messiah who would rescue the "silent majority" and the "real France" from "immoral", leftist values. Moral, or immoral, leftism had infected the whole nation since the student revolt of 1968, he said. That implicitly included the several centre-right governments to which Sarkozy has belonged.

All this has made for an absorbing French election, lacking only a twist in the final chapter.

Sarkozy has led the polls since mid-January, and topped the first round poll two weeks ago with 31% of the vote to Royal's 25.8%. To win today, she would need to take over half of the centrist vote (over 18% of the total) which went to Francois Bayrou in the first round.

Most older centrist voters have . . . very reluctantly in many cases . . . decided to go along with Sarkozy. Some of the younger ones have switched to Royal, but not enough for her to win: the final polls gave her opponent a lead of between 6% and 9%.

Much of the "wider", or harder left, electorate will turn out for Royal, but they represented only about 10% of the total vote in the first round. One way and another, the whole political spectrum in France has shifted radically to the Right in 2007.

That will not prevent the trade unions from opposing Sarkozy's economic and social reforms. His likely prime minister, the smooth and handsome Francois Fillon, says that a crash programme will be pushed though the new parliament in July.

This would probably include . . .

shades of Margaret Thatcher . . .

changes in trade union law to impose secret ballots for strikes longer than eight days and to force unions to operate a "minimum" train and bus service during stoppages.

The unions will oppose these changes on the streets in September. Which of the two Sarkozys will respond to their challenge? The reasonable man who debated on Wednesday, or the fiery crusader for the silent majority?

Sarkozy is no ultra-capitalist, whatever the unions might say.

Nor is he likely to be an easy partner for Britain in Europe. He believes in creating French, or European, champion industries.

He wants European trade barriers against alleged "dumping" by the Chinese or developing world.

He wants EU governments, not the markets, to fix the value of the Euro. He promises to defend the European farm policy, and even to move it back to its pricefixing glory days.

Britain's own leader in waiting, Gordon Brown, knows Nicolas Sarkozy well from EU meetings of finance ministers. They are said to get on.

However, in the long run, their relationship is likely to be no happier than that between Tony Blair and Jacques Chirac.