Bob Filner is scheduled to return to work Monday, but a city attorney could seek a restraining order barring him from city hall. NBC's Joe Fryer reports.

SAN DIEGO - The effort to recall San Diego's scandal-struck mayor kicked off on Sunday, the eve of Bob Filner's scheduled return to work at City Hall after undergoing behavioral therapy.

Bill Wechter / Getty Images Mayor Bob Filner of San Diego arrives at a press conference to announce his intention to seek professional help for sexual harassment issues on July 26, 2013.

The drive to oust Filner, which comes amid a flurry of sexual harassment allegations, faces a monumental challenge because of the extremely tight time limits, according to U-T San Diego newspaper.

The 70-year-old has resisted numerous calls to resign after more than a dozen women publicly accused him of making inappropriate statements or advances.

Several recall-related events took place Sunday around San Diego, NBCSanDiego.com reported. At 1 p.m. local time, recall organizers attended a “Recall Signature –Gathering” kick-off event. Those who attended learned about how to become a volunteer for the recall effort and were given petitions to sign and mail back to organizers.

At another afternoon rally in downtown San Diego, organizers delivered short speeches before taking to the streets to march.

"Are you ready to take back our city?" one organizer asked the crowd, NBCSAnDiego.com reported. “Bob Filner, the citizens of San Diego have a message for you: It’s time to resign."

More on Bob Filner scandal from NBCSanDiego.com

Gloria Allred, an attorney representing some of the women accusing Filner of sexual harassment, also spoke at the rally.

"Mayor Bob Filner, you do not share our dream of gender equality," Allred said. "City Hall is not your personal sexual playground."

Attorney Gloria Allred and Peggy Shannon, the latest woman to accuse San Diego Mayor Bob Filner of sexual harassment, discuss the mayor's lewd behavior towards women on MSNBC's Hardball.

Volunteers spread out across San Diego, the country's eighth-largest city, to ask voters to help press for the petition, which must gather 101,597 valid signatures.

Organizers must collect the required amount of signatures of registered San Diego voters by Sept. 26, but if it has fewer than that, the campaign will have 30 more days to circulate a supplemental petition to gather the additional valid signatures.

Organizers also set up the website Recall Bob Filner Now!, which includes a real-time mapping function for petition drive locations and petition forms to download and circulate.

"This is a tremendous grassroots undertaking — truly the people taking back their government from an abuser who has betrayed San Diegans, demeaned women and who can no longer lead our city," The Associated Press quoted Michael Pallamary, who filed the petition to recall the Democrat. "They're ready to tell Filner, 'It's over, Bob. The people are going to show you the door.'"

House Minority Leader Nancy Pelosi, one of the numerous public people who have called for Filner's resignation, has said that he should spare San Diego the pain and expense of a recall election.

On Thursday a volunteer city worker who assists senior citizens said Filner repeatedly rubbed her hands, asked her on dates and made sexually suggestive comments.

Recall organizers say they have raised more than $100,000 so far and more than 800 people have signed up to volunteer for the effort, the AP reported.