After a year of quietly laying groundwork and making institutional inroads in the federal regulatory agencies, the consumer movement is now hoping to cash in.

"It's going to be a much more exciting year," promises Ralph Nader, "and it's not going to see the kind of consumer movement that the Business Roundtable, with a few flicks of the corporate tail, can stop dead on the Hill."

Nader is referring, of course, to the resounding defeat of the proposed federal Consumer Agency Bill by Congress early this year following an intensive lobbying campaign against it by business.

Although that legislation would have established a federal agency to represent the consumer before various government regulatory agencies, consumer advocates say they must have accomplished much of that goal in other ways.

Besides the creation of consumer advocacy offices in several federal agencies - many of which provide funding for consumers to appear before agency proceedings - even more consumer advocates have taken jobs on the inside of the government. And White House consumer advocate Esther Peterson has been given a broadened policy role including the task of overseeing each of the agencies' efforts for consumers.

Peterson's role is critical to a consumer movement that hopes to take advantage of its institutional inroads into government.

After Congress defeated Peterson's pet project, the consumer agency, she was close to leaving the government. But President Carter convinced her to stay in government with the promise that he would give her a voice in any major administration proposals that might affect the consumer.

There has been real progress," Peterson said in a recent interview. "We are far more into the decision-making process. When decisions are made, we are now, by authority of the president, able to say no, because it will hurt the consumer too much."

She already has had an impact on decisions concerning meat export policy and sugar pricing. In addition, her office is evaluating all consumer offices throughout the government. It also has begun updating the decade-old Truth in Lending Law.

And Peterson is sitting in on more and more conference meetings on the Hill, gaining direct access to appropriation decisions for departments such as Agriculture and Energy.

The newest consumer advocate to head a federal agency is Susan King, a 38-year-old veteran political activist who was named in June to head the beleaguered Consumer Product Safety Commission.

"The role of the consumer has become institutionalized," she said in one of the first interviews of her tenure. "There is a heightened awareness and concern over consumer issues, especially concerning safety."

A July Louis Harris survey backs up much of what King says. Some 74 percent of more than 1,500 people surveyed gave a high priority to making products and services safer, "up from 65 percent two years ago," Harris says.

King already has pumped new life into the small five-year-old agency. "We have made gains here," she said, referring to consumerists in the government. "We have sensitized people to issues like chemicals in their clothing, sugar in cereals, pesticides in the environment - we can now say we have a more demanding consumer. People are reading labels."

For her part, King has severely cut the number of projects her agency is targeting for the coming year, and is devoting more time and effort to the more important ones. "We are looking at the things the consumer feels he or she has less control over, like aluminum wiring, fire hazards in upholstery, carcinogens in many consumer products and others," she explained.

"I'm not wild about generic 'think safety' campaigns," she said, preferring instead to go after safety programs aimed at skateboarders and people planning to insulate their homes.

And King is overseeing a critical joint program with the chain saw industry in which that industry will set its own safety standards - under the guidance of the commission and outside consumers - and theoretically save the government a hugh amount of money it would have had to spend to set a mandatory standard.

The chain saw experiment is critical because it will test the level of cooperation business will give to government.

"If we don't like the standard, or the industry is not following it, we will step in," King said. "But at least that is one industry that saw what was coming if they did not cooperate, and decided it would be better for everybody for them to work with us."

But for the most part, "Industry has not borne its responsibility of checking in advance to see if what they're doing is safe," King said. "Nobody ever ordered clothing manufacturers to use Tris, we just told them to make their garments flame resistant. It was their responsibility to see that they were not causing more problems with their solution.

Nader agrees that corporate America is not doing its part, and he is taking what he calls appropriation action.

"We're going for justice in the courts by expanding consumer class action rights and remedies," he said. "And we are going to expand the organization of consumer power through co-ops."

In fact, a major victory for consumers in 1978 was passage of the Co-op Bank Bill authorizing creation of a federal bank to make loans to consumer cooperatives set up to provide everything from health care to food.

There is some progress coming from industry in its outlook toward consumers, including indications that cousumer issues are being taken more seriously.

In a study entitled "The Rising Tide of Consumerism," Washington public relations consultant Edie Fraser of Fraser Associates tells her clients that "individual trade associations are mounting their own consumer programs . . . More trade associations have hired professionals, several as officers, to serve the consumer function.

"The growth of consumer affairs in industry is best represented by the phenomenal growth of the Society of Consumer Affairs Professionals in Business since 1973," Fraser wrote. Membership in that group has swelled from a handful to more than 1,000 member professionals. And "surveys indicate that consumer affairs are increasingly handled by top management," Fraser pointed out.

But for all the gains, there is a long way to go," a pessimistic Nader said. "We're not going to forget the defeat of the consumer agency." He said there couldn't be better people in office. "Claybrook, Foreman, Pertschuk - you'll never get better people. But they are still mired in the trivial things and unable to brak out of their pits to get things done," he said.