Can French conservatives and Socialists learn to work together?

Wearing corduroys and a sports jacket, Henri Chabert dresses the part of a French preppie. He represents the conservative neo-Gaullist Rally for the Republic as a city councillor in Lyon. Wearing a somber brown suit, Guy Fischer looks the part of the working-man leader. He represents the Communist Party as mayor of this suburb of Lyon.

Yet, despite their political differences, Mr. Fischer and Mr. Chabert now work together. They have drawn up a plan to redevelop this grimy, dilapidated suburb.

Can France's leaders forge the same cooperation on a national level? That question dominates the final moments of the campaign for Sunday's parliamentary elections.

If the conservatives win a parliamentary majority, as predicted, Socialist President Fran,cois Mitterrand will likely appoint a conservative prime minister -- a situation unprecedented since the Fifth Republic was founded in 1958. Many political analysts say that prolonged political instability could result.

Whatever the outcome, this election marks a turning point for the nation.

In his five years in office, President Mitterrand has solidified France's position among Western allies. At home, he has rather ironically settled France firmly into a free-enterprise system.

Mitterrand's political transformation has been dramatic. After coming to power in 1981, he instituted radical social reforms and embarked on an spending binge to create jobs at a time when the rest of Europe was retrenching. Then he changed course, clamped on austerity measures and evolved into what might be seen as a moderate social democrat. The change turned the Socialists into the country's major party on the left and devastated the Communist Party.

As a result, ideology almost has disappeared from political debate. Five years ago, the French faced a choice between Marxism or capitalism. Today, as Gaullist Chabert notes, ``everyone agrees on a liberal, individualistic society.'' Only a difference in emphasis remains.

The resulting campaign has been largely flat and colorless. With inflation down and economic growth up, the Socialists have argued that their austerity has France on the mend. The conservatives have responded by saying they can best complete the job.

Within these narrowed electoral debates, both sides have relied increasingly on American-style hoopla. Mitterrand himself charged to the front-lines, descending from his throne-like office in the Elys'ee Palace to address rallies and television audiences on behalf of his party. His tactics may have brought some success: Opinion polls of his own performance, which had fallen to a 25-percent favorable rating in 1984, have risen to 46 percent today. His efforts may have helped his party narrow the gap a bit in the campaign's final weeks.

On the stump, Mitterrand's message has been simple: Help me avoid a crisis. In a television appearance last week, he spoke of the problems which would ensue if the conservatives win. ``If the majority is hostile to the President,'' Mitterrand said, ``there will be disorder, some very serious problems, a difficult period.''

To Americans, used to a president and a congress coming from opposing parties, Mitterrand's statement might sound like an exaggeration. But to the French, the prospect of what they call ``cohabitation'' sounds alarming. Until now Mitterrand and every other president in the 28-year history of the Fifth Republic has enjoyed a supportive legislative majority.

Since Mitterrand's term runs until 1988, a conservative victory Sunday would make power sharing necessary. Politicians and analysts have been imagining scenarios for every eventuality in the coming drama of power sharing.

The prospect threatens both foreign and domestic policy. Pessimists predict that France is moving back toward the coalition building of the post-war Fourth Republic, which went through 26 cabinets in 11 years.

The need to share power could weaken the considerable powers of the presidency. Former President Charles de Gaulle created the Fifth Republic in his authoritarian image, making the presidency the most powerful office in the country. ``The French President is the only king in a modern democracy,'' says Philippe Moreau Defarges, an analyst at the French Institute for Foreign Relations, a private think tank.

Under the Constitution, the President has the power to dissolve Parliament, to name a prime minister, and to oversee national defense as commander in chief. Mitterrand has said that if he is forced to accept a non-Socialist prime minister, he will use the leverage these powers give him to direct foreign policy.

``No one is going to hide me behind a pot of flowers,'' he says.

Opposition leaders such as neo-Gaullist Jacques Chirac and former President Val'ery Giscard d'Estaing would like to do just that. Both men have posed conditions under which they would agree to work with the Socialist President. As the front-runner for the post of prime minister, Mr. Chirac insists on guarantees that the President would not obstruct his planned economic policies.

A strong political motivation may increase the chances for successful ``cohabitation.'' Both Chirac and Mitterrand want to position themselves well for the next presidential elections. Chirac wants two year's experience as prime minister to make him the opposition's undisputed leader. Mitterrand, on the other hand, believes that the opposition could quickly land in trouble if it doesn't come up with cures for unemployment and other economic problems after winning a majority. Then he might win a second term.

Last of series. Previous pieces ran March 7, 10, 11, and 12.