The Communists decided Thursday to break their alliance with the Socialists and not join the new French government, further confirming President Francois Mitterrand's shift to the political center.
As Prime Minister Laurent Fabius was choosing his new Cabinet, Communist Party spokesman Pierre Juquin announced his party could no longer support a government more interested in combating inflation and budget deficits than unemployment. He said the Communists would abandon the four Cabinet posts they had held since the left came to power in 1981, although they would continue to support the Socialists in the National Assembly.
''The prime minister repeated that he had decided to continue the austerity policy which will translate into an increase in unemployment and the deteriorating of purchasing power and salaries,'' Juquin explained.
The departure of Transportation Minister Charles Fiterman and his three Communist colleagues will allow President Francois Mitterrand to work with a more moderate Cabinet team which is more in tune with him not only politically, but also personally. Socialist Party faithful and proteges of the President dominate the new Cabinet. Foreign Minister Claude Cheysson and Defense Minister Charles Hernu retained their posts, while Interior Minister Gaston Deferre moved to planning and regional development. He was replaced by Socialist parliamentary whip Pierre Joxe.
The major shift, though, was at finance. Respected economist Jacques Delors will move on to the presidency of the European Commission and be replaced by former Social Affairs Minister Pierre Beregovoy. Mr. Delors was the architect of the tough economic austerity program, but he was not trusted in the Socialist Party.
Beregovoy has a proper Socialist Party pedigree and was Mitterrand's chief adviser at the Elysee before taking the social affairs portfolio. At that ministry, he proved a tough administrator, closing a yawning budget deficit with cuts in welfare benefits. No change is expected in Delors' stringent fiscal policies.
''The economic policies are not going to be different,'' Socialist Party chief Lionel Jospin predicted flatly.
That was exactly what the Communists could no longer accept. For months, they had been sniping as the government's economic policies let unemployment soar above 2 million. In the spring, party leader Georges Marchais even criticized then Industry Minister Fabius by name for his decision to close steel plants, while calling for a policy of massive industrial subsidies and increased social benefits. Political considerations also figured in the Communists' departure. Staying in a government they were criticizing was proving costly with the faithful. In the June elections for the European Parliament, they suffered a disaster, winning only 11.2 percent of the vote. Now the Communists will be free to increase their attacks even more, in the hope this tactic will unite the party and pick up disgruntled voters.
But leaving has its liabilities as well. It deprives the party of the legitimacy of government participation. Moreover, despite their attempt to censure the Socialists, the Communists are bound to be blamed for the rupture, just as they were when they split the union of the left in 1977. Looking like spoilers could further erode the party's support, and put it in a political ghetto.
That has been Mitterrand's goal since the 1960s. When he became Socialist Party leader in 1969, he was junior partner to the Communists. By the mid-1970s he had turned the Communists into the junior partner by offering a viable leftist, non-Marxist, alternative.
Now as President, Mitterrand has decided he no longer needs the Communists. The Socialist majority in the National Assembly is sufficient to let him rule alone. And he figured the Communists were as much a drag as a boost to his government.
Where the Communists can still hurt him is on the streets and the factory floors. The party-led union, the Confederation Generale du Travail, is the country's largest. It could mobilize large demonstrations and strikes.
Still, Mitterrand decided it was time to take the risk. His government is unpopular, and he has only 21 months before the next parliamentary election. To win, he will need to gain young, moderate votes, and analysts figure that discarding the Communists will make it easier for them to vote Socialist.
The new government will try to attract these voters with economic results. While the austerity program has increased unemployment, it has brought down the country's inflation rate, trade deficit, and debt load.
This will permit a significant tax cut, and in an ironic twist on conservative Reaganism across the Atlantic, a potential Socialist supply-side recovery.