John Ray maintains a substantial lead in the campaign for the D.C. Democratic mayoral nomination, while Charlene Drew Jarvis has doubled her support since May to pull ahead of the other three leading candidates in the final two weeks of the race, according to a Washington Post survey.

Ray, a D.C. Council member making his third bid for mayor, is the current choice of 33 percent of the registered Democrats interviewed, while Jarvis is supported by 17 percent. Del. Walter E. Fauntroy and Sharon Pratt Dixon, a lawyer and party activist, were tied at 10 percent, while Council Chairman David A. Clarke was supported by 9 percent of those polled.

In the campaign for the party's nomination for delegate to Congress, Eleanor Holmes Norton, a former Carter administration official, holds a similarly strong lead over five other Democratic candidates, according to the survey.

The poll found that about half, 48 percent, said it was fairly important or very important that Mayor Marion Barry's successor be a black person, a view expressed by equal proportions of blacks and whites in the District. Clarke is the only white candidate in the race.

Most voters said the contest for mayor had focused on personalities rather than issues confronting the District. Two of every 10 voters interviewed said they haven't decided whom to support.

The Post poll also found that most voters are concerned that the local real estate industry, which has contributed more than $600,000 to the mayoral candidates, has exerted too much influence in the race leading to the Sept. 11 primary.

Ray has been criticized by Fauntroy and other opponents for accepting large contributions from real estate interests.

Barry, who plans to run as an independent for a D.C. Council seat in the wake of his drug conspiracy trial, would receive about a third of the vote in that election this fall, the survey found.

If that support holds, the three-term mayor, who is awaiting sentencing on a misdemeanor cocaine possession conviction, would be in a strong position to capture one of the two available at-large council seats on the November ballot.

The survey of 668 registered Democrats -- a snapshot of voter attitudes in the unsettled primary election campaign -- found that Ray has increased his lead in recent months, as he has stepped up his media campaign and picked up important endorsements.

In May, Ray was the choice of 23 percent of those Democrats interviewed, exactly the same percentage that favored Barry, who had not yet abandoned plans to run for a fourth term. Jarvis was the choice of only 7 percent of those questioned in the earlier poll. Support for the remaining candidates was virtually unchanged from the last Post poll.

Twenty-one percent of those surveyed were undecided, supported another candidate or said they likely would not vote in the Democratic primary.

While the intense publicity surrounding Barry's arrest and trial has put something of a damper on this election season, the survey shows that support for the mayoral candidates is now slowly coalescing.

However, about half of the registered Democrats who were surveyed described their support for their current choice as weak, suggesting that the race could be won in the final days of what has become an increasingly contentious campaign. In May, a Post poll found two-thirds of those Democratic voters interviewed expressing soft support for their choices.

Slightly more than half of Ray's supporters, 53 percent, said their support for him was somewhat soft. In May, 60 percent of Ray's support was that weak.

Among Jarvis's supporters, just over half characterized their support as "not strong." In May, that figure was 27 percent.

Despite his lead, Ray said yesterday he considered himself "the dark horse. I have to go out and work and earn my votes every day."

He also said he was taking steps to strengthen his support with direct mail to households and door-to-door leafleting in targeted precincts.

"This is the hour that you have to encompass all those things," Ray said.

Bill Jarvis, who is managing his aunt's campaign, said the survey confirms that her bid "has momentum, the Ray campaign is stagnant, and it's a two-person race."

David E. Byrd, Dixon's top aide, said the poll showed her ability to "move ahead of people with 16, 19 years of experience in local politics. The undecided is waiting for someone; the soft support needs leadership."

Kerry Pearson, Clarke's campaign manager, said, "With the combination of the undecideds and the softness of the vote, the poll proves that the contest is wide open."

Fauntroy spokesman Robert L. Johnson said, "This election is by no means over because John Ray, for all of his money, has not convinced the voters of the District of Columbia that he should be mayor, and they have the same doubts about Charlene Jarvis."

The mayoral candidates will face each other tonight in the first major televised debate of the campaign, to be broadcast by WUSA-TV (Channel 9) from 10 to 11 p.m.

In the race to succeed Fauntroy as delegate, Norton led the field with 31 percent, followed by Sterling Tucker, 19 percent; Betty Ann Kane, 15 percent; Joseph P. Yeldell, 8 percent; Donald M. Temple, 4 percent; and Barbara Lett Simmons, 4 percent.

Nineteen percent were undecided, said they supported some other candidate or indicated they probably would not vote in the delegate's election.

This most recent survey suggests that none of the mayoral candidates benefited significantly from Barry's June 13 announcement that he would not seek election to a fourth term as mayor. Barry supporters appeared to have scattered among the remaining five candidates, with about a third currently supporting Ray and about a quarter backing Jarvis.

Barry has not yet indicated which candidate he favors, although he has held open the possibility of endorsing a candidate before the Democratic primary.

According to the poll, both Ray and Jarvis appear to draw support from all segments of the community. Blacks make up about 75 percent of the Democratic vote in the District and a similar share of Ray and Jarvis supporters, while the rest are white.

Half of Dixon's support comes from white voters. Four of every 10 voters currently supporting Clarke are white.

Fauntroy's supporters are disproportionately black; more than nine out of 10 voters questioned who support Fauntroy are black.

Although women make up 57 percent of D.C.'s Democratic voters, the survey found no candidate currently enjoys a disproportionately large share of the vote among women. Meanwhile, neither Dixon nor Jarvis, who have contended their campaigns may be hurt by a bias against women candidates, appear to be heavily penalized by voters on that basis.

According to the poll, 48 percent of Dixon's supporters are men, as are 43 percent of all Jarvis supporters. Women make up 57 percent of the support for Ray, 54 percent for Fauntroy and 55 percent of Clarke's support.

Overall, 21 percent of those questioned said it was at least "fairly important" or "very important" that the next mayor be a man, a view that was expressed by equal percentages of men and women. Another 24 percent said it was not too important, while a majority, 54 percent, said it was not important at all.

When asked about issues facing the city, voters listed drugs and crime as the main problems they want the next mayor to work hardest to solve. At the same time, the survey suggests the Democratic mayoral primary has largely been a referendum on personal character and past experience, rather than the candidates' specific stands on issues.

Senior polling analyst Sharon Warden contributed to this report.