D.C. Council member Jack Evans (D-Ward 2) is planning something unusual for his birthday tomorrow -- he's going to file papers declaring himself a candidate for mayor of the District.

"I'm ready to go out and begin campaigning," Evans said yesterday.

Evans, a lawyer who has held his council seat since 1991, said he is running for mayor "to clean up the mess" in the city government.

"I feel I've done as much as I can on the council to address those issues," he said. "Only as the executive can I get the results I'm trying to achieve."

Notwithstanding the diminished power of the mayor's office since August, when Congress transferred much of the authority for government to the federally appointed D.C. financial control board, Evans said he still thinks the job is the most influential in the city.

Mayor Marion Barry (D), who is serving his fourth term, has not said whether he will seek reelection next year. Asked about Evans's candidacy at his weekly news conference yesterday, Barry flashed a grin and said, "The first shall be last, and the last shall be first."

At least three of Evans's council colleagues -- Harold Brazil (D-At Large), Kevin P. Chavous (D-Ward 7) and Carol Schwartz (R-At Large) -- have said they were considering mayoral candidacies for next year.

Two people already have filed papers declaring their candidacies: Jeffrey Gildenhorn, a Ward 3 businessman, and Ernest Johnson, a Northwest Washington community activist. Evans's campaign team includes Warren Graves, a former director of communications for the Barry administration who will serve as campaign manager. For treasurer, Evans has tapped Walter Beach, who served as treasurer in the two mayoral campaigns of Walter E. Washington. His campaign chairman is Bill Jarvis, a lawyer and nephew of council member Charlene Drew Jarvis (D-Ward 4), who ran twice for mayor.

Evans, who turns 44 tomorrow, and his wife, Noel, are the parents of 1-year-old triplets. He said he has no qualms about the prospect of a mayoral campaign and is prepared to campaign for the next year.

"I will be there on Election Day, Sept. 15, in the Democratic primary and be there again in November and will be sworn in as mayor in 1999," he said.