Trying to distinguish himself in a crowded field of Democrats eyeing the mayoralty, City Council Speaker Gifford Miller has hired heavyweight political strategist Mandy Grunwald to mold him into a serious contender, sources close to the speaker disclosed yesterday.

The addition of Ms. Grunwald, who coordinated press coverage for President Clinton, is the latest effort by the speaker to surround himself with seasoned political veterans with a knack for devising sound bites designed to appeal to the masses.

His director of communications, Stephen Sigmund, organized Mark Green’s 2001 mayoral campaign. His press secretary, David Chai, was Al Gore’s spokesman in California during the 2000 presidential campaign. Both joined the speaker in February.

Mr. Miller, an adept fund-raiser who leads the money race among potential candidates with $3.3 million, will likely rely on Ms. Grunwald to help him project an image of an experienced politician with a dignified demeanor.

Despite holding what is regarded as the second-most powerful office in city government, the 35-year-old speaker has struggled to overcome the perception that he does not have the resume or the wisdom that comes with age to run the city.

To give an indication of the ubiquity of that perception, Mr. Miller was recently lampooned as a lollipop-carrying Little Lord Fauntleroy at an annual parody of local politicians and the press.

“Grunwald’s chief goal will be to strategically transmit a sense of gravitas about Miller,” said Doug Muzzio, a public policy professor at Baruch College. “One of the things he has to overcome is his youthfulness and youthful look.”

As Democratic strategists go, Ms. Grunwald has long been considered one of the powerhouses. People describe her as a sharp, no-nonsense, ideologically committed liberal.

Ms. Grunwald, who declined requests for comment and abruptly hung up when reached by phone, made her name defending the Clintons on “Nightline” over the Gennifer Flowers scandal during the 1992 presidential campaign.

She later made television commercials for three of Senator Daniel Patrick Moynihan’s campaigns, and softened Hillary Clinton’s image with a “listening tour” through New York State leading up to the 2000 election.

Less notably, she worked unsuccessfully this year to convince New Hampshire voters of Senator Lieberman’s electability.

“Having someone with her track record and connections to the Clintons is a sign that Miller can attract high-level help, which is a sign of his seriousness,” said Steven Cohen, a political science professor at Columbia University.

In signing on to Mr. Miller’s camp, Ms. Grunwald inherits an indefatigable campaigner who single-handedly engineered his rise to speaker in 2001 by contributing to the campaigns of select council members and tirelessly stumping with them in their districts. Fellow council members elect the speaker.

Yet for all the traveling he did to become speaker, and the coordinated visits around the five boroughs he has made since, polls show Mr. Miller is largely unknown outside city government and has little in the way of a natural constituency.

Unlike other possible mayoral candidates whose ethnicity or middle-class background may automatically curry favor with wide segments of the electorate, Mr. Miller hails from the Upper East Side of Manhattan – an area once known as “the silk stocking district.”

“He is a total white-bread, white guy who doesn’t bring any of that favorite son stuff to his candidacy,” said Joseph Mercurio, a political consultant working on the mayoral campaign of the Manhattan borough president, C. Virginia Fields. “He’s the most underrated politician in New York and you can’t rule out Gifford Miller in any election,” he added. “But you have to have a natural constituency and he doesn’t have that.”