President Valery Giscard d'Estaing of France apparently is positioning his forces to go on the offensive against the scandals and criticisms that present a danger for his reelection.

In the face of growing apprehension among leadership groups in Giscard's own center-right electorate, a concerted effort has been made by the Elysee Palace to remove the scent of scandal created around the president by such things as the undeclared gifts of diamonds to Giscard and his family by Central Africa's deposed Emperor Jean-Bedel Bokassa and the imprisonment for about seven months of Roger Delpey, a French writer to whom Bokassa had confided his story and the documents to back it up.

Close collaborators of the president recently invited representatives of Socialist leader Francois Mitterrand and Gaullist leader Jacques Chirac around to tell them that the diamonds have now all been, as the Elysee Palace officials put it, "recuperated" and are being sold off for charity, the weekly Canard Enchaine is planning to reveal Wednesday.

The officials also reportedly noted that it was the Elysee that had Delpey released. An Elysee spokesman confirmed that the conversation with a Socialist representative had taken place at the palace, but he would not comment on the meeting with the Gaullist that the weekly said took place in a private home.

Chirac was quoted as saying of the episode of the man Paris headline writers have dubbed "the president's prisoner" that "it was a good thing to get him out of prison, but perhaps it would have been even better not to have put him in there in the first place."

As soon as Giscard is no longer bound by his "obligation" to speak with reserve as long as he has not announced his candidacy, he will "respond to a series of problems and I can tell you that his answer will be rough," said former Interior Minister Michel Poniatowski, considered the president's closest confidant.

The president's efforts to pull the fangs out of the affairs well in advance of the election in May could be a response to the growing feeling expressed in banking and industry circles that have constituted Giscard's single most important source of support that he has too many malodorous cans tied to his tail and that it would perhaps be better for all concerned if he did not run.

Delpey went out of his way to stress upon his release from prison that he had made no deals and that if he had agreed to be freed, it was not "to keep quiet." In interviews with a number of publications, including The Washington Post, Delpey insisted that his book is just about ready for the publishers and that he will bring it out in February -- shortly before the elections.

While he described the diamonds as being "only the tip of the iceberg," Delpey said he was keeping his other revelations for the book and for use at other times and places. He did allege that Bokassa had once given France's first lady, Anne-Aymone Giscard d'Estaing, a gift of exactly 100 diamonds.

The writer-adventurer said he spent 41 days out of a period of eight months interviewing Bokassa almost full-time during five visits to him in and out of power. The emperor and the president had a falling out over Giscard's demands that Bokassa assign about 50 Central African soldiers and guards to provide permanent security at a hunting ground of nearly 1.4 million acres that the African ruler had given to the French leader as a gift, he added.

Delpey said the book would also back up Bokassa's contention that allegations that the emperor personally took part in the massacre of children were cleverly concocted and orchestrated by French intelligence to clear the way for his overthrow by French troops in September 1979.

The slight, red-faced and mustachioed Delpey, 56, was a Gaullist and a sergeant during the French Indochina war, about which he wrote a series of four bestselling novels. He said he first decided to go to Central Africa, as the government's guest, because he could not believe that a former French Army officer like Bokassa could possibly have committed the kinds of atrocities he had been accused of.

Delpey said he was aware of a deal offered a few weeks ago through his lawyers for his freedom: dropping the charges against him and a passport to go live in Spain if he would reveal the whereabouts of 187 documents Bokassa had given him for the book. Delpey indicated that the documents are in safekeeping somewhere in Switzerland.

Delpey insists that, far from being a Libyan agent as he has been accused, the five visits the police observed him making to the Libyan Embassy here were simply to transmit messages from Bokassa to a Central African living in Libya to get $500,000 the deposed emperor had on deposit at a bank in Tripoli transferred via a Swiss bank to his exile in Abidjan, Ivory Coast.

Delpey said he never managed to get the money transferred, and that contrary to press reports that when arrested he was carrying a huge amount of money the Libyans had given him, "I had exactly 239 francs [about $60] on me."

If he had not been released, said Delpey, he would have arranged for publication one by one of the documents he has. "I couldn't see myself sitting in prison until the presidential elections," he said.

But despite all his disclaimers, there are persons connected with the affair and sympathetic to his cause who still privately voice suspicions that he may have made some sort of deal.

According to the Canard Enchaine, Jacques Wahl, secretary general of the Elysee, told Mitterrand's representative that the president had been shocked by the attacks Socialist leaders have made on his political and personal morality and expressed a desire that the tone of the reelection campaign be elevated now that major reproaches against Giscaard had been corrected.

That very weekend, Giscardist candidates were eliminated across the board in seven parliamentary by-elections in which Gaullists, socialists and communists ganged up against the president's men. The normally progovernment weekly Le Point did a cover story entitled: "Can Giscard be beaten?"

This followed another cover story by the leftist Nouvel Observateur showing Giscard, his parents, wife, brother and cousin under the headline "Giscard & Co. How a bourgeois dynasty turned power into a family business."

"Personally," retorted the French first lady in an interview, "the president and I often feel like taking a rest and not continuing to bear such a heavy burden for him. . . . But he will never do anything that could damage the interests of France. If it appeared necessary for the interests of France for him to run for president again, I think he would do it."