Mayoral candidate Morris Harper and Marie Bembery, the only announced Democratic challenger to D.C. Del. Walter E. Fauntroy, both failed to meet a 5 p.m. Wednesday deadline for filing petitions to run in the city's Sept. 14 primary.

Bembery was barred from filing by the D.C. Board of Elections and Ethics when a campaign aide who was holding the majority of her nominating petitions failed to step inside the room with her before the door was closed. Bembery said yesterday she has appealed to the elections board, and a hearing has been set for next week on her case.

"The law says don't accept any petitions after 5 o'clock," said Ted Filosofos, elections administrator. "If she wants to go to court then she can take us to court."

Harper, a Washington physician who faces an elections board hearing on allegations that he filed a false and misleading campaign finance report, had turned in fewer than the required 2,000 signatures for the mayor's race by the 5 p.m. deadline Wednesday, Filosofos said.

Dennis P. Sobin, a publisher who had announced for mayor as a Democrat, decided to run as an independent and therefore did not file Wednesday. Sylvia Vacchio, Sobin's campaign director, said Sobin "changed his affliliation to independent." She complained that as a Democrat, Sobin was often excluded from candidate forums by sponsors who allegedly felt his views were too unorthodox or liberal.

Only persons wishing to run as Democrats, Republicans or Statehood party candidates were required to file petitions by July 7, and only candidates for those parties' nominations will appear on the ballot in the Sept. 14 primary. Persons running as independents or under other party designations have until Aug. 25 to file and will appear only on the general election ballot in November.

Candidates filing in party primaries for city offices were:

Mayor: Democrats--Mayor Marion Barry, Patricia Roberts Harris, At-large City Council member John Ray, Ward 4 City Council member Charlene Drew Jarvis. Republicans--James Champagne and E. Brooke Lee Jr.

Council Chairman: Democrats--Incumbent Arrington Dixon, Ward 1 councilman David A. Clarke, former council chairman Sterling Tucker. Republicans--none.

Council At Large: Democrats--Incumbent Betty Ann Kane, school board member Barbara Lett Simmons, Johnny Barnes, Patricia Wells, Osie L. Thorpe. Republicans--None. Statehood Party--incumbent Hilda Mason.

Ward 1: Democrats--Glenn L. Reitze, Frank Smith, Reuben Lewis, Ester L. McCain Jr., Marie Nahikian, Calvin O. Wingfield. Republicans--Charles B. Fisher, Nancy Shia, Jacob Sherrill Jr.

Ward 3: Democrats--Incumbent Polly Shackleton, Mark Plotkin, Ruth Dixon. Republicans--Lois DeVecchio.

Ward 5: Democrats--Incumbent William R. Spaulding, Douglas E. Moore, Robert I. Artisst, Robert King, Richard S. Lee, Rufus T. Langford. Republican--William R. Evans.

Ward 6: Democrats--Incumbent Nadine P. Winter, John Warren. Republicans--None.

D.C. Delegate: Democrat--Walter E. Fauntroy. Republicans--Viola E. James, John West.