Representatives of Patricia Roberts Harris, currently running second in the polls for Tuesday's D.C. Democratic mayoral primary, have urged Charlene Drew Jarvis to drop out of the race and support Harris, thereby boosting Harris' chances for a come-from-behind victory over Mayor Marion Barry.

Harris, a lawyer and former Carter administration cabinet member, has run significantly behind Barry in recent polls. However, her own most recent surveys indicate she is closing the gap with four days left before the election, campaign aides said yesterday.

Advisers to Harris have considered Jarvis, the City Council member representing voter-rich Ward 4 in upper Northwest Washington, a tough competitor for support from women and middle-class voters, and also a candidate who has appeared hopelessly behind in most polls.

Last Tuesday afternoon, Harris fund-raisers Oliver T. Carr Jr. and Joyce Siegel met at the Hotel Washington with Woodrow Boggs Jr., manager of the Jarvis campaign, and contended that Jarvis should not stand in the way of a possible Harris victory.

"I feel it is in Charlene's best interest not to be a spoiler," Carr said yesterday, recalling the meeting. "She has gained recognition and credibility as well as presenting herself very well. I also said it would be to Harris' advantage to have a one-on-one race," which the Harris campaign would prefer but the Barry camp would not.

Boggs said yesterday that Jarvis had been leaning toward supporting Harris if she decided to leave the contest, but was angered when Harris campaign workers challenged the validity of signatures on Jarvis' candidacy petitions.

Boggs said that since then, Jarvis has been waiting in vain for a personal apology. "Harris threw a rock at her and when it missed, she said, 'Okay, do you want to come in and join us,' " Boggs said.

Jarvis said yesterday that she is still in the race. "I think neither of the candidates Barry or Harris is secure in their feeling of strength." She said she also had received calls from Barry campaign aides that she suspected were on the same topic.

"The calls are a reflection of that and the fact that I feel growth in my own candidacy," Jarvis said.

Top Barry campaign aides were unavailable yesterday for comment.

In a separate campaign development yesterday, the political arm of the Greater Washington Board of Trade found itself divided on the Democratic mayoral rivals and declined to endorse any of the candidates. The board chose instead to donate $2,000 to each of four Democratic contenders -- an apparent victory for Harris.

But on another front, the editorial page of The Washington Post, whose endorsement was considered a key to Barry's victory in 1978 and whose support campaigners for Harris had viewed as crucial this year, endorsed Barry for reelection in this morning's editions.

"We don't say he has been perfect," the endorsement read. "We say he has been a good mayor, that he has worked hard and made a substantial difference in the city -- and that he deserves a chance to continue the job."

The Post also endorsed former City Council chairman Sterling Tucker, who lost a 1978 bid for mayor, for election to his old job, bypassing incumbent Arrington Dixon, whom the paper supporterd in 1978, and council member David A. Clarke.

In other council races, The Post endorsed incumbents Betty Ann Kane for the Democratic nomination for an at-large seat, Nadine P. Winter in Ward 6, Polly Shackleton in Ward 3, William R. Spaulding in Ward 5 and school board member Frank Smith in Ward 1.

The board of trade is the major group representing the city's business community and has been highly supportive of Mayor Barry's reelection campaign.

However, the board's 11-member political action committee includes several supporters of Harris, among them developer Oliver T. Carr Jr. and realtor Flaxie M. Pinkett, cochairmen of Harris' campaign finance committee.

A source who attended the committee's meeting cited these divisions as the reason no endorsement was made.

However, an official board spokesman played down divisions on the committee, insisting that the panel found all four Democratic contenders acceptable.

Meanwhile, it was confirmed yesterday that an earlier Barry endorsement--that of the American Federation of Government Employees (AFGE)--is being investigated by the Office of Special Counsel of the federal Merit Systems Protection Board to determine whether the union violated the Hatch Act, which prohibits partisan political activity by federal or D.C. employes.

AFGE, which said it had never before endorsed a political candidate in its 50 years, voted 5,867 to 131 on May 18 to endorse Barry at a meeting to which 65 union locals sent representatives, according to the union publication, The Government Standard. AFGE represents about 8,000 D.C. employes.

Under the Hatch Act, federal employes are barred from "endorsing or opposing a candidate . . . in a political advertisement, a broadcast, campaign, literature or similar material."

AFGE national Vice President Donald M. MacIntyre, who had sent a mailing to AFGE members on June 25, describing the vote to "endorse" Barry as a "giant step forward" for the union, said yesterday he erred in using the word "endorsement." The May 18 vote, he said, was actually a "poll," and the actual endorsement was made later by union officials who are not active federal employes and therefore not bound by the Hatch Act.

With time running increasingly short before the Tuesday primary, Harris and her top aides claimed yesterday that her $200,000 television advertising campaign, which was launched last month, has begun to turn the campaign more in their favor. A poll conducted for the campaign last Monday and Tuesday by Peter D. Hart Research Associates indicated that Harris is running far better than before among the city's black voters and has significantly narrowed Barry's lead, according to Sharon Pratt Dixon, Harris' campaign director. The percentage of undecided voters also has increased, according to Dixon.

A WRC-TV/Associated Press poll conducted Aug. 25-26 showed Barry holding a 16-point lead over Harris among likely Democratic primary voters, with 10 percent undecided.

Dixon said the new Harris poll shows that Harris has made sizable gains in Wards 4 and 5, middle-class black areas in Northwest and Northeast Washington, and holds a substantial lead over Barry in Ward 3, the affluent, mostly white area west of Rock Creek Park.

"There's no doubt about it -- the campaign has been clicking on all cylinders for the last 15 days," said Harris pollster and adviser Peter Hart, although he declined to release specifics about the poll. "The TV ads have been superband that's been the difference. We're getting our message across in a straight, undiluted way."

Barry said this week he is still confident of winning more than 50 percent of the Democratic vote, but he has cautioned his campaign staff against complacency in the final week before next Tuesday's election. "We never concern ourselves with what the other candidates are doing," said Lea Adams, Barry's campaign press secretary.

Washington Post staff writers Peter Perl and Eric Pianin contributed to this article.