Bettie J. Robinson, the acting director of the D.C. Office of Consumer Protection, said yesterday that her agency change is reducing its backlog of cases, contrary to a charge by Democratic mayoral candidate Sterling Tucker.

In a position paper issued last Friday, Tucker charged that the consumer protection office's backlog had increased from 639 last December to 1,847 by June 30. Robinson conceded the accuracy of the June figure, but said that was a decrease from a backlog of 2073 last December.

There was no ready explanation for the widely different December figures. Robinson said: "You ask Tucker about the discrepancy. I've given you the facts. The only explanation is that this is all political."

Tucker spokesman Sherwood Ross said he could not explain the discrepancy.

Robinson said that Tucker "demonstrated incredible irresponsiblity in attacking" the consumer protection office "to further his own political ambitions."

She conceded some of Tucker's allegations that various functions in the office had not been performed on time, but said that they occurred before she became acting director on March 20.

But she demanded a retraction for one Tucker statement that "dismissal proceedings" were pending against her at the time she was named acting director. D.C. personnel director George R. Harrod said Friday that criticisms of Robinson by her predecessor. Edith Barksdale Sloan, were "almost hearsay" and that "there's no validity" to them. He said there never have been dismissal proceedings against Robinson.

"Mrs. Robinson may be technically correct in her statement about dismissal proceedings," Ross said. "Clearly, the recommendation of her superior that she be transferred or removed from the office indicated her superior's belief of a lack of suitability for the job."