As Michel Bordaz remembers it, the workers in his factory drank a victory toast when Francois Mitterrand brought socialism to power in France last spring.

Mitterrand had promised them "change" and, sure enough, his very victory altered labor relations in the Lyons washing machine factory where Bordaz has worked for the past 12 years at a salary just above the legal minimum.

"The first thing we noticed was the difference in the way the superintendents treat us," said Bordaz, a delegate for the country's Socialist-oriented union, the French Democratic Labor Confederation. "The discipline changed. We didn't have to worry so much about drinking a coffee or talking with our friends. The factory is going to be nationalized. That is a real factor. They are thinking of their future."

The shift described by Bordaz for about 1,500 workers at his Thomson-CSF factory here reflected Mitterrand's pledges to nationalize eight major industries and 39 private banks as part of a Socialist effort to reduce France's 8.5 percent unemployment and give workers a bigger place in a revitalized economy.

Denounced by businessmen as outdated, naive and potentially disastrous, the Socialist platform has in the eight months since Mitterrand's victory brought psychological and economic gains to the 17 million French workers like Bordaz.

If the businessmen and some conservative economists are right, the president's policies will in the long run make life harder for rich and poor alike. They have complained about the new income surtax, increased payroll and expense-account taxes and the government's changes in work schedules. But they also fear that the program's result will be more fundamental and will set new criteria for business decisions--employment rather than profit, for example--and that the French economy will come out a loser.

Already 14 percent inflation is catching up with the gains, and grumbling is heard on the factory floor. But, in the meantime, Bordaz and his fellows at the low end of the pay scale have won swift advantages from government efforts to stimulate the economy through increased consumption.

For Bordaz, 39, increases in child support payments boosted the subsidy he and his wife receive to care for their three children by one-fourth, bringing the total to $250 a month. At the same time, the guaranteed miniumum wage has jumped from $456 a month in June to $542 a month, pushing up Bordaz'ssalary to $586 a month.

For Marie-Rose Julien, a 32-year-old mother who earns the minimum wage at the Dupre Coathanger factory in nearby Saint-Etienne, the difference meant paying "less attention" to costs at Christmas this year when buying gifts for her 7-year-old daughter, Carole.

The government at the same time has increased rent subsidies by 50 percent in two steps, raised unemployment insurance payments, twice increased old-age pensions and included in its budget plans to add 71,000 jobs in the civil service and hospitals.

But Bordaz and Julien, because their spouses work, are ineligible for these benefits, except, they both pointed out, in the long-term view that higher pensions will be welcome when they retire.

Despite the salary and benefit increases, however, Bordaz calculates that inflation has taken back what Prime Minister Pierre Mauroy handed out. "Whatever they say, the result is a loss in buying power," he said over a beer in a Lyons bar.

But workers realize the need to accept inflation as a price for reducing unemployment, he added, and rises in the cost of living have not brought on the same discontent they caused under President Valery Giscard d'Estaing, when Prime Minister Raymond Barre held down wages to suppress inflation.

The Socialist government has lost support, however, because of a growing fear that a gap is opening between what Mitterrand promised as a candidate and what he is delivering as president, he said, echoing complaints of other normally pro-Socialist workers.

"They workers thought everything that was promised in the campaign--retirement at 60, 55 for the women perhaps, that the bosses would be controlled--they thought this would be put into practice by laws that would come down immediately," Bordaz explained. "The idea that people were sold out is not far off."

The nationalizations that were a key component of Mitterrand's campaign platform have been delayed by a court ruling that several provisions of the government's legislation--particularly reimbursement scales--were unconstitutional. The laws have now been revised and passed again by parliament and are expected to be put into practice within several weeks.

Ironically, a government decree to fix the legal work week at 39 hours and the legal paid vacation at five weeks instead of four also has contributed to the dissatisfaction. Since the decree did not define whether workers would be paid for the full 40 hours or lose an hour's pay, conflicts broke out last week in factories across France.

Bordaz and his colleagues staged a brief work stoppage Friday to underline their insistence that the 40th hour be paid in full.

Julien, a delegate for the same union, said she and her fellow delegates at Dupre are being asked why the government cannot simply impose the full weekly salary as part of its decree.

Behind the questions, Bordaz said, is a concern for worker power that ran through much of last spring's support for Mitterrand. This will be a key question as the government seeks to reform labor laws this spring in line with another campaign promise, he added.

"Workers attach a lot of importance to guarantees of jobs from the nationalizations," he said. "And they also want social guarantees, such as when you need to take a day off. As it is now, you have to kind of beg. It's sort of according to each customer. That gives the superintendents opportunity for a lot of funny business."