One of the most significant developments in District politics over the past several years -- with important implications for the next mayor -- has been the gradual acquisition of power by the D.C. Council.

With little notice or fanfare, the council has collected broad new authority in recent years: powers ranging from the right to review and approve the food service contract for the Washington Convention Center to taking control of the sale of surplus city property.

Last week, the council approved yet another major expansion of its power, granting itself emergency authority to review any city contract worth more than $1 million in the final months of the Barry administration. Some council members say they may make the measure permanent in time for the new mayor's administration.

Dealing with a newly assertive council undoubtedly will be a minefield for the next mayor, especially if Republican Maurice T. Turner Jr. scores an upset.

Even if Democrat Sharon Pratt Dixon wins the general election, as expected, she may find moving her programs and budgets through the Democratic-

controlled legislature more difficult than expected.

A newcomer to electoral politics, Dixon has few natural allies on the council; two of the people she defeated in the Democratic primary will remain on the body and the likely next council chairman, John A. Wilson, has made clear his intent to establish the council as a "co-equal" branch of government.

Some council insiders fear this mix is a recipe for legislative gridlock or, indeed, for council dominance of the policy-making process -- especially if Mayor Marion Barry wins election to one of it at-large seats.

They fear that Barry will use his longstanding ties to key players in the bureaucracy to undermine Dixon's bold promises to "clean house" in D.C. government and reduce the city payroll. With other potential obstacles thrown up by such powerful committee heads as Charlene Drew Jarvis (D-Ward 4) and John Ray (D-At Large), as well as Wilson, Dixon could enjoy a relatively short honeymoon in office.

"I see the potential for a whole lot of trouble," said one veteran council insider.

Officially, Dixon seems to be trying earnestly to lay the groundwork for a governing coalition on the 13-member council. She has met with most council members, and even some of those who opposed her in the primary, such as H.R. Crawford (D-Ward 7), have expressed support for her.

Indeed, in the waning months of the Barry administration, some council members are doing all they can to make sure Dixon has the opportunity for a fresh start. Part of the impetus behind the council's move to restrict Barry's contracting power is a desire to prevent the possibility that the mayor might give away the store before he leaves office Jan. 1.

Some council members also are trying to bottle up four of Barry's proposed appointments to the D.C. Taxicab Commission, so Dixon has an opportunity to make her own appointments to that rate-setting body.

"It is very clear that council members have evidenced a willingness to work with her," said William Lightfoot (I-At Large), who is expected to be one of Dixon's main allies on the council.

Lightfoot acknowledged that the council has assumed more responsibility for the management of government in recent years, but he described this trend as an effort to correct the posture of too much deference to Barry in his early years in office. "We're going to have to be dealt with," he said. "It used to be the mayor dictated to us."

Jim Nathanson (D-Ward 3), another council member expected to play a greater role in coming years, said he sees no serious problems because many members of the council share Dixon's commitment to keeping the lid on tax increases and cutting the bureaucracy.

But he also said the council may well take an assertive role on finance and other matters in the first few months of the new administration, as Dixon sinks her teeth into the huge District bureaucracy. "The council will be leading initially while she learns her way around," Nathanson said.