Esther Peterson, President Carter's consumer adviser, has been trying since August to arrange a meeting with her successor in the Reagan administration, Virginia Knauer, to discuss United Nations draft guidelines on international consumer protection.

But before arranging a meeting, the Consumer Affairs Office asked the Justice Department whether Peterson should be required to register as a foreign agent. The reason: the International Organization of Consumers Unions (IOCU), for which Peterson is lobbying, is headquartered in the Netherlands.

"It was not a minor thing," explained Joseph C. Dawson, information director in the Consumer Affairs Office. "When Esther first requested that meeting, there was a story in The Washington Post about someone in the government meeting with someone who was not registered as a foreign agent. We wanted to get clearance from Justice on this thing."

But to Peterson -- who has been called a lot of things, but never a foreign agent -- this latest round with the Reagan administration is a laughing matter. "I really get kind of a kick out of it," she said. "The way they talk about 'foreign agent,' I feel like I'm in a spy book."

In a letter to the Justice Department, the Consumer Affairs Office general counsel, Michael J. Stewart, wrote: "A preliminary reading of the Foreign Agents Registration Act raises the distinct possibility that Ms. Peterson may actually be acting as an agent of a foreign principal and, therefore, would seem to be required to file a registration statement with the Attorney General . . . . "

The Justice Department still has the matter "under review. No decision has been reached," according to press spokesman John Russell. But a department lawyer did advise Knauer's office earlier that it was okay for her to meet with predecessor Peterson even if she is a foreign agent.

Peterson, once called the "grande dame of consumerism," with presidential connections going back to the Johnson administration, is pressing for U.S. support of proposed U.N. guidelines on consumer protection around the world. The guidelines would set nonbinding international standards on such things as food, water and pharmaceutical products for developing countries that want to establish their own consumer protection rules.

Peterson contended that the concern over her "foreign agent" status stems from the administration's opposition to the U.N. draft guidelines. "It's obvious they don't want to talk to me," she said. "I'd be ashamed of their position, too."

But Dawson, the Consumer Affairs Office spokesman, called that nonsense. The query to Justice, he said, "had no impact at all on us trying to set up a meeting." Dawson said it was Peterson, not Knauer, who canceled the first proposed meeting in October and has been unable to attend on any suggested alternate dates.

A new round of letters went out this week with Peterson and Knauer each blaming the other for the delays. The United Nations is scheduled to debate the guidelines in New York Nov. 12.

Meanwhile, Peterson said she wrote to the Justice Department and volunteered to register as a foreign agent. "Why shouldn't I?" she said.