The FN, fresh from its pivotal mayoral victory in Vitrolles, is holding a national conference, at which some of its own ugliness and internal tensions might have been expected to be on display.
Instead, attention is likely to focus on the huge anti-Front demonstrations planned in the Alsatian city, which, on past experience, may end in violent confrontations between the more militant anti-Frontistes and the riot police.
The Front leader, Jean-Marie Le Pen will be able, and is already preparing, to present himself in his favoured role of victim. In an interview with Le Figaro yesterday, he said that it was dangerous to democracy that a "large political organisation", commanding the votes of up to 15 per cent of the French electorate, was not permitted to conduct a legal gathering in peace.
Up to 30,000 demonstrators are expected from all over France, Germany, Italy and Switzerland. The political establishment risks looking all the more ridiculous because there will not be one but two anti-Front demonstrations, a big one supported by the left and a smaller one organised by the centre- right. Amid the brouhaha, there may be little focus on events at the three- day Easter conference itself where, behind a facade of unity, the FN is facing awkward tactical decisions and the beginnings of an internal power struggle.
The Strasbourg conference exemplifies the problems of the French democratic establishment in dealing with an outwardly democratic party which espouses ultimately undemocratic ideas. When the Front has been ignored in the last 15 years, its influence, unopposed, has tended to grow.
When the centre right has cooperated with the FN, hoping to take over part of its support, the opposite has happened and Frontiste influence has tended to grow. When the Front has been stridently opposed by both left and right, its preoccupations with race and national identity have been placed at centre stage and its influence has tended to grow.
Long-term adversaries and students of Front strategy say the best method of containing this advance, which is disturbing but not as powerful as is imagined, is systematically and laboriously to fight FN ideas and activism at the most basic, grass-roots, political level.
While the other French parties have suffered from the withering of political participation, seen in many democratic countries in recent years, the Front has been busy building a network of local and special-interest organisations. (There are now FN trades unions, FN youth groups and 32 FN single-issue fronts for everything from animal rights to old people).
Catherine Trautmann, the Socialist mayor of Strasbourg, has had some success in checking the FN in her city by counter-activity at street level. But it was she who called on anti-FN forces to come to the city this weekend to mount the kind of public protests which are emotionally satisfying but which can be counter-productive.
The Front National has a similar conference every three years without attracting such large demonstrations. Temperatures have been raised on this occasion by several factors.
First, the FN victory in the mayoral election in Vitrolles, near Marseilles, last month, brought the number of far-right-controlled towns in France to four. Vitrolles was the first time the FN had scored an outright majority in normal conditions against all other parties.
Second, the stakes were further raised last month by the intellectual- and artist-led campaign against a new law to control illegal immigration, which was held by the "cultural left" to be an example of the creeping "Le-Pennisation" of French politics.
Thirdly, a modest to powerful FN showing of 15 to 17 per cent could be enough to give Mr Le Pen a block of MPs in the parliamentary elections next March and offer him new opportunities to disrupt mainstream politics.
Fourthly, there is a convergence of factors which tend to help the FN's cause: the high rate of unemployment; the acute French fear of globalisation; the undercurrent of fear of Europe and the Euro; and the drip-drip of financial scandal in all the other parties, except the Communists.
These are reasons enough to fear the potential strength of the FN. But it is also important to dwell on the Front's weaknesses. Jean-Marie Le Pen is the most widely feared and detested politician in France, topping all political unpopularity contests (79 per cent "negatives" in one recent poll). In all tests of opinion, an overwhelming majority of French people - at least 65 per cent, depending on the question - say they would never vote for the Front. (Against that, 30 per cent have already done so at one time or another).
Victory in Vitrolles was an important watershed for the FN. But it has brought its own problems. Even though his wife's name was on the ballot paper, Vitrolles was a de facto victory for Bruno Megret, the de facto Number Two of the Front National. Mr Megret, 48 next week, expects to be the FN's presidential candidate in 2002. So does Mr Le Pen, who is 70 next year. In his Figaro interview yesterday, Mr Le Pen brusquely rejected the suggestion that it was time to prepare his succession. "Why? Do you think I'm too old. I am not as old as Deng Xiaoping," he said.
Since Vitrolles, relations between Mr Le Pen and Mr Megret, difficult for several years, have been chilly, according to sources within the party. Mr Le Pen resents the fact that, for the first time, there is a power base within the party that is independent of "Le Chef".
More galling still, Mr Megret is the most likely FN candidate to win a parliamentary seat next year (in Vitrolles and the neighbouring town). Mr Le Pen has not nursed a constituency and knows he will face carpet- bombing by the establishment wherever he plants his flag. A vain man, he hates the idea that Mr Megret might win while he loses. He also hates the idea of not running at all and leaving Mr Megret as the FN leader in parliament.
The conference might give some clue to his intentions. But in the face of the challenge on the streets outside, whether peaceful or violent, the FN will be determined to put on a show of unity.