The authority of France's Socialist government is being put to the test by a series of street demonstrations involving students, farmers and small businessmen that have led to several clashes with the police.

The demonstrations, which have been growing in size over the past two weeks, have invited ironic talk about a "1968 in reverse." In May 1968, leftist students and workers almost succeeded in toppling the conservative government of Gen. Charles de Gaulle. This year, it is a left-wing administration that is in power, and the challenge is coming from the right.

The consensus among most French commentators and politicians, however, is that the present round of unrest is very different from the strikes and student protests of 15 years ago, as well as being much smaller in scale. Apart from general dissatisfaction with the government, there is no sense of ideological unity among the different groups of protesters. Each group is concerned above all with promoting its own sectional grievances.

The superficial comparison with 1968 stems largely from what again has become the common sight of masked student demonstrators building barricades and hurling rocks and molotov cocktails at the police in the twisting streets of the Latin Quarter in Paris. Taunted by chants of "Hot, hot, hot, the springtime will be hot," the police have replied with water cannons, tear gas and charges with clubs.

In Paris yesterday, the riot police were confronted simultaneously by about 8,000 students protesting planned university reforms and about 20,000 small businessmen and shopkeepers complaining about higher taxes. About 100 police and at least 30 demonstrators were treated for minor injuries after street fighting broke out at the end of what otherwise were orderly marches. The clashes continued until early this morning.

While all this was going on, several hundred farmers were herding their sheep through the center of the capital in a peaceful protest against what they consider low prices for their produce. More violent demonstrations have taken place in other parts of France, notably Brittany in the northwest where pig farmers have stormed a police station and set fire to public buildings.

Today trouble spread to Nice in the south where 200 students occupied the law school of the city university and science students declared a strike.

Faced with this sudden upsurge of protest, the government has had the difficult choice either of attempting to ride it out or buying off the demonstrators with concessions. Both courses of action carry risks. Ignoring the demonstrations invites fresh protest, while giving in creates an impression of weakness that the authorities are anxious to avoid.

The real threat to the government is not that it will be overthrown--its parliamentary majority is so solid that it easily can ride out any challenge from diverse groups of protesters in the streets--but that its will to implement reforms and impose an austerity program will be sapped. There already have been indications that ministers may be willing to modify a proposed new education law that has been the immediate cause of much of the unrest.

Students complain that the draft bill, which is due to be debated in the National Assembly on May 24, will introduce much more rigorous selection procedures at the end of the second university year. The government insists that the aim is to make the universities at once more responsive to the needs of society and also more democratic because of a relaxation in entry requirements.

A six-week strike by medical students and hospital interns worried about their future careers was suspended earlier this week following concessions by the prime minister, Pierre Mauroy. In the meantime, however, protests over the same issue spread to the schools of law and economic sciences in Paris and several provincial universities. The law school, in particular, has had a traditional reputation for right-wing sympathies, and this has encouraged left-wing charges that the protests are being manipulated for political purposes. Le Matin, a newspaper that generally supports the government, published documents earlier this week purporting to show that the organizers of the demonstrations were connected to extreme rightist groups.

The protests so far have failed to win any significant support from trade unions, despite the fact that the government's austerity measures are likely to lead to a cut in the standard of living. They have been condemned by the Communist Party, which controls the largest union federation in France, the CGT.

Edmond Maire, the head of the second largest union, CFDT, said that--unlike the revolt of 1968--the present protests lacked "a collective dynamic."

A similar point was made by one of the student leaders of 1968, Daniel Cohn-Bendit, who said in a radio interview that the present strains were caused largely by "worry about the future" at a time when youth unemployment is extremely high. The 1968 crisis, by contrast, coincided with a period of rapid economic growth and represented a questioning by youth of the direction in which society was moving.

Not the least of the ironies about the present situation is that some of the former student rebels are now writing editorials in left-wing newspapers implicitly criticizing the latest protests. By contrast, Le Figaro, the right-wing newspaper that usually supports "law and order" positions, openly sympathizes with the demonstrators and gloats over the government's difficulties.