WHEN Francois Mitterrand named Edith Cresson as France's first woman prime minister in May, the French president said he wanted a "boisterous debate" to give the country a "new impetus."Four months later, most of the debate here swirls around Mr. Mitterrand himself. Polls have consistently shown the French public's low esteem for Mrs. Cresson, causing as many doubts about the president's wisdom as about his new prime minister's abilities. Fast-rising unemployment has hit 2.7 million French, nearly 10 percent of the working population, leading to dissatisfaction with the president's economic course. Naming Cresson, who is further left on the political spectrum than her predecessor, Michel Rocard, seemed to indicate that the Socialist president hoped to reanimate French political debate by taking the government to the left. But that move seemed to misjudge public sentiment. Polls show the country's center-right parties winning a comfortable majority if legislative elections, set for 1993, were held now. On the international scene, the alacrity with which Mitterrand appeared to accept the arrival of "Moscow's new leaders" only hours after the Soviet coup attempt was announced shocked the French, who had long considered their president a master of foreign affairs. As a result, the pre-summer debate encapsulated in the "10 years is enough!" slogan - Mitterrand was elected in 1981 and reelected in 1988 - has built up steam. A survey released last week by the weekly L'Express showed 61 percent consider the president "worn out." Mitterrand responded to such criticisms in a general press conference on Wednesday - only the sixth of his 10 years in office. It was designed to reassure the French and remind the nation's political and economic partners that "France is a great country, one of the most present" in international affairs. Mitterrand called for a meeting of the four powers holding nuclear weapons in Europe - France, the United States, the Soviet Union, and Britain - to ensure the continent's security. He referred to the "uncertainty" coming from Moscow. "It's up to Moscow, to say where we are on this, who holds the authority, where [its] nuclear arms are, and, where they are going," he said. But that proposal is unlikely to please Germany, which, although it has no nuclear arms, has insisted it has a place in discussions on European security. In a tack more to Bonn's liking, Mitterrand shifted French policy further on Yugoslavia, saying it is his "hypothesis" that the republics of Slovenia and Croatia will be independent. In a message to his European Community partners, the French president said it is "imperative" that the 12 EC countries complete negotiations on deeper economic and political integration by December. Any delay would signal a return to "struggles for influence" and the "game of alliances," and would reduce the EC to a free-trade zone - something he said "certain countries of the Community hope for." Stung by criticism from EC partners as well as Eastern Europe, Mitterrand also appeared to adopt a more conciliatory position following France's move last week to block the lowering of Community barriers to Eastern European farm products. France is not opposed to imports and wants quick conclusion of association agreements between the EC and Poland, Czechoslovakia, and Hungary, Mitterrand said. He reiterated French support for "a type of Marshall Plan" for the East, a triangular arrangement by which the EC would buy up Eastern European farm surpluses to offer as winter food assistance to Moscow. Still, Mitterrand's primary purpose was to speak to the French and debunk speculation that his leadership is spent. He also pronounced himself "very happy" with his choice of Cresson. He announced a further evolution in his privatization policy, saying he had authorized the government to sell minority interests in some publicly held companies. Finally, Mitterrand indicated that "the time will come" to eventually take up one of his earlier proposals to reduce the French president's term from seven to five years. But he obviously didn't want to appear to justify talk of the "wear and tear of power" by bringing it up now.