Former Veterans Administration chief Robert P. Nimmo, who resigned under fire in 1982, recently discovered how quickly political promises can evaporate in a presidential election year.

At a Republican fund-raiser in San Luis Obispo, Calif., in late August, Interior Secretary William P. Clark Jr. asked Nimmo if he would serve on a Bureau of Land Management advisory committee.

The committee was later identified as the 21-member National Public Lands Advisory Council, which makes recommendations on managing federal lands.

"Bob Nimmo and I found out very early in Washington that to do the things that the president promised in 1980 you have to step on some sacred toes in the bureaucracy," Clark was quoted by the San Luis Obispo County Telegram & Tribune as saying at the dinner. He then hinted that Nimmo was forced to resign by federal bureaucrats because he made waves.

Nimmo stepped down in October 1982, just ahead of a General Accounting Office report that criticized his use of a chartered military aircraft, first-class air travel and a personal chauffeur in violation of the law. He reimbursed the government $6,441 for the chauffeur.

Last Thursday, when the newspaper article about the dinner appeared in Interior's daily news summary, Clark spokesman Rusty Brashear denied that Nimmo had been offered a job.

"There's no truth to any of this," Brashear said. "It's really a mysterious thing. There is more wrong in that story than in any I've ever seen."

However, Nimmo said in a telephone interview the next day that Clark had offered him the job. "He mentioned it to me just shortly before the dinner," Nimmo said. "I asked him how much time it would take, and he said, 'Not much,' so I said I would be happy to do it."

Al Mittelstaedt, who wrote the story, also produced a tape-recording of Clark's remarks.

"The article was closer to being correct than we realized," Brashear said yesterday. But he insisted that the newspaper account and Clark's remarks "probably implied more than what was there."

He said Clark had mentioned the advisory post in passing, but had forgotten about the matter when he discovered that there "wouldn't be any openings on the commission for at least one year." Brashear said Clark called Nimmo on Friday to tell him that there wouldn't be an appointment because there "was nothing available."

However, a BLM official said yesterday that there will be seven openings at the end of December.

Brashear rejected a suggestion that Clark might have retracted the offer out of concern that it might embarrass the administration.

During the summer the the appointment of former Environmental Protection Agency administrator Anne M. Burford to an advisory committee on environmental policy set off a flurry of complaints. Burford later decided not to accept the post.