By unanimously approving broad new oversight powers for themselves this week, Chairman-Elect John A. Wilson and other members of the D.C. Council sent an unmistakable signal to Mayor-Elect Sharon Pratt Dixon that they are determined to be an equal partner with her in running the city's government.

The bill, approved Tuesday, gives the council authority to review and reject any D.C. contract or lease worth more than $1 million, giving legislators the opportunity to delve into what had previously been an executive branch prerogative.

What's more, the council disregarded the last-minute entreaties of Dixon, who personally telephoned most council members and urged them to reject a measure she said would hinder her efforts to reform D.C. government. Council member Harry Thomas Sr. (D-Ward 5), the only member to publicly pledge to stand by Dixon on the issue, changed his mind and voted with the rest of his colleagues.

Fresh from her landslide victory over Republican Maurice T. Turner Jr. in the general election, Dixon's legislative setback is far from crippling. She enjoys considerable goodwill among some council members and other politicians.

But the vote highlights the considerable job Dixon has cut out for her in establishing a working relationship with council members -- including some she belittled as "blind mice" during the mayoral campaign -- according to some council members, staff and other observers.

"She ran her campaign as an outsider," said Joslyn N. Williams, chairman of the D.C. Democratic State Committee. "She trashed the mayor. She trashed the council. Now she's going to have to develop a rapport with the council that does not exist now. She'll have to be patient."

Dixon's relationship with the council is likely to be far different from that enjoyed by outgoing Mayor Marion Barry. Barry served on the council for four years before he was elected to his first term as mayor in 1978. By the time he took office, he had already forged an alliance with many key council members.

Barry also savored the rough and tumble of deal-making with individual council members. Until late in his tenure, he usually could count on a majority of the 13 members to pass his budgets and legislative initiatives.

By contrast, Dixon is far less familiar with many of the council members. Her closest ally on the council next year is expected to be freshman Harold Brazil (D-Ward 6), a former colleague at Potomac Electric Power Co.

It will take time, council members say, for Dixon to develop the same kind of influence Barry enjoyed for so many years on the council. "Nobody here owes her anything," said one longtime council aide. "It is going to be very, very difficult to get the council to approve major pieces of reform legislation."

Dixon's aides yesterday played down the significance of the council's vote Tuesday. "I think she recognizes there is going to be give and take with the council and a lot of shifting back and forth," said Dixon spokesman Paul Costello. "She didn't see it as a test of her authority or the council's authority."

Dixon believes the council was reacting to "genuine past abuses" of the contracting process by Barry and responding to "the same mandate that put her in office," Costello said.

However, privately Dixon has been more critical of the council's action and has expressed annoyance, in particular, with Wilson for not being more cooperative.

Wilson yesterday defended the legislation as an important step toward reestablishing a balance of power between the executive and legislative branches. Wilson contends that the council was deferential for too long toward Barry's policies and programs.

"I have no personal animosity or anything," Wilson said. "There needs to be a much more level playing field, and that's what I'm interested in establishing."

"I want to be supportive" of Dixon, Wilson said. But he added, "I don't want to lose my political identity."

Other council members and staff members said that Dixon misplayed her first legislative struggle with the council by elevating the contracts bill into a major and highly personal issue. She told at least one member that she viewed the bill as a "personal affront."

At the same time, Wilson was in an extremely strong position with his colleagues because of his important role in handing out much desired committee assignments. Some council members who might otherwise be supportive of Dixon are leery of crossing Wilson now.

"It was self-flagellation," council member Jim Nathanson (D-Ward 3) said of Dixon's effort to kill the bill. "Dixon picked an issue on which she knew she was going to lose."

"She handled it very badly," added one Dixon transition committee member. "She said, 'I don't want it,' and it wasn't as if there was room for compromise."

Dixon may eventually prevail on the issue, however. The council must vote again on the proposal on second reading, and Dixon could prevail on Barry to veto the measure. "I don't count these things as victories," Wilson said yesterday, "because with this body, things can turn around in 48 hours."