D.C. City Councilman Marion Barry challenged the nomination petitions of two little-known rivals in the mayoral race yesterday, just minutes before the deadline. One of the candidates charged it was an effort to knock him from the top spot on the Democratic primary ballot.

James Clark, who last week won the lead position in a field of seven candidates on the ballot in a Board of Elections and Ethics lottery, said yesterday the challenge was politically motivated because Barry has the second spot on the ballot.

"I knew they were going to try and do that," Clark said in a telephone interview. "Barry's trying to get the number one spot, but I'm not worried. I've got enough signatures."

Two of Barry's campaign workers, Phil Ogilvie and Jeanette Michael, filed the challenges against Clark and Wilmur A. Davis just 10 minutes before the 5 p.m. deadline yesterday, the last day challenges could be filed.

Candidates for mayor in the Democratic Primary need the signatures of 1,826 registered Democrats to qualify, said Mary Rodgers, Board of Elections administrator. Rogers said hearings on the challenges will be scheduled "as soon as possible."

Barry's campaign manager, Ivanhoe Donaldson, denied that the challenge against Clark was done to remove him from the top spot on the ballot. Donaldson said both Clark and Davis were challenged because "their petitions aren't legal."

Davis could not be reached for comment.

Frank Sewell, a candidate for mayor in the D.C. Statehood Party primary, has been challenged by Richard Brunning.

In one of the races for an at-large seat, candidate JePhunneh Lawrence has challenged the petitions of Absalom F. Jordan Jr., a staff aide to councilman and council chairman candidate Douglas Moore.

Four of five candidates in the Ward 1 race, including incumbent David A. Clarke, also were challenged. The others are Frank Smith, Samuel B. Wallace and James B. Scott.