French President Valery Giscard d'Estaing and officials of his government went on the offensive today to denounce recent attacks against Jews and proclaim the unity of France in opposing racism and anti-Semitism.

Accused by critics of keeping silent too long, Giscard went on television to reassure France's 600,000-member Jewish community that the nation will stand united to "face the threat that is throwing us back to the hideous germs of intolerance and racism."

The president's unscheduled television appearance followed a Cabinet meeting largely devoted to discussion of the effect of the recent attacks on ethnic and race relations in France.

Giscard said he had ordered government representatives in the country's 95 administrative regions to call meetings on Friday with local religious, labor union and human rights representatives to show their solidarity and examine problems affecting the security of local community groups.

Giscard's address followed a march in Paris last night by a crowd estimated at at least 100,000 to protest a recent attack on a Paris synagogue that killed four persons.

Many demonstrators chanted antigovernment slogans including "Giscard and Bonnet [Interior Minister Christian Bonnet], accomplices to murder!" a

Bonnet has been singled out by Jewish activists and opposition leaders who allege that he allowed police to neglect the growth of neo-Nazi groups in France.

Earlier, at the start of an emergency debate in the National Assembly, Prime Minister Raymond Barre said accusations of laxity against the authorities were defamatory and scandalous.

Barre said the synagogue attack was intended to set off a chain of violence in France aimed at threatening the democratic basis of French society. He appealed to the French "not to react to provocative acts from whatever quarter.

Socialist Party leader Francois Mitterrand read out a long list of racist and anti-Semitic attacks in France in recent years, most of them unpunished, and told the government deputies: "The victims have the feeling that they were not under your protection."

He accused the government of expending all its energies on repressing left-wing terrorism and making no attempt to halt the resurgence of fascism.

In the first reported act of Jewish retaliation for the recent attacks, a group calling itself the Jewish Brigades claimed responsibility for an attack in which a youth threw acid into the face of Charles Bousquet, an 84-year-old suburban Paris resident.

The attacker drew a Star of David on the wall after throwing acid and police said it was an apparent case of mistaken identity because Bousquet, who was seriously injured, had the same last name as an editor of a rightist newsletter.

Anonymous callers said others were on Jewish Brigades' blacklist of neofascists and that the next victims would be killed.