(AP) San Diego Mayor Bob Filner. (AP)

The drumbeat to oust San Diego Mayor Bob Filner, 70, who is accused of being a serial sexual harasser, just keeps getting louder.

So loud, it seems, that his lawyers announced late Friday he had quit intensive in-patient psychotherapy sooner than the two weeks he originally planned. As of Saturday, he plans to spend the next week away from work, receiving outpatient treatment, and will “not be available for comment,” reports the Associated Press.

Small wonder, given that among the alleged predator’s latest accusers are two female veterans, women who report enduring military sexual assaults along with the ever-present risk of enemy-inflicted physical injury.

This week, four of them outed Filner for unwanted advances during and after his 20 years in Congress, which included a stint chairing the House Veterans Affairs Committee. That makes 13 women who’ve come forward since mid-July, a scant eight months after his November election.

Their allegations moved Sen. Barbara Boxer, D-Cal., to demand in a letter to the intransigent and incommunicado Filner that he resign, as reported by Politico.

“I have worked for so many years to prevent and punish sexual violence and sexual harassment, wherever they occur. As we fight in the Senate to stand up for the men and women in our military who are survivors of sexual assault, I have heard their stories, seen the anguish in their faces, listened to them talk about the pain that will always be with them,” she wrote to him, sparing no subtly. “Let me be clear: The latest revelations regarding your behavior toward women recovering from sexual assault – women who desperately need our help – have shaken me to my core,”

This is apparently what drove her anger.

On Aug. 7, Retired Air Force master sergeant Eldonna Fernandez cited Filner’s “creepy” 2012 voice mail asking her out, after she spoke publicly about her three rapes while in the service. Vetern Gerri Tindley, who told CNN she’d been raped while in the Army, recalled nearly falling off a sofa to evade his advances last year during the same conference on sexual harassment and assault sponsored by the National Women Veterans Association of America.

On Aug. 6, nurse Michelle Tyler told KPBS that Filner came on to her after she sought his help getting better stateside treatment for Katherine Ragazzino, a former Marine who spent 18 months in an Iraq hospital after a severe brain injury and post-traumatic stress disorder. Tyler said Filner rubbed her arm while proposing what she deemed an unwelcome bargain: He would help with Ragazzino’s bureaucratic problems if Tyler had dinner with him.

Boxer is among a growing list of politicians seeking Filner’s resignation, including Sen. Dianne Feinstein, Rep. Susan Davis, his Democratic successor,  and Debbie Wasserman Scultz, D-Fla., who chairs the Democratic National Committee.

Ditto for former mayor Jerry Sanders, who just disinvited Filner from a late September trip to Washington with the San Deigo Regional Chamber of Commerce.

“We simply cannot risk any major distraction that would further impede the region’s business,” he wrote to Filner. He, too, suggested the mayor get it over with and resign.

Critical mass seems to be building. Already one of the “Filner Thirteen-and-Counting” has filed suit, with the ferocious workplace rights attorney Gloria Allred naming as defendants the mayor and the city, which has refused to pay for Filner’s private counsel. There is no predicting how many other women will seek legal redress.

But even before the sex scandal broke, land surveyor Michael Pallamary planned a recall drive based on what he considers Filner’s “political power grabbing.” Opponents  can start gathering the required 102,000 signatures beginning Aug. 18.

Pallamary cited several instances of Filner imposing his own agenda on initiatives after they’d been approved, and pressuring developers to support his pet causes. The U-T San Diego newspaper reported July 3 that federal officials are probing a developer’s $100,000 donation to the city as he sought the mayor’s approval for changes in a project. The money has since been returned

Pallamary also fears the fallout from the sexual allegations. “Every minute he stays in office, he extends the city’s exposure to lawsuits.  At his press conference, he admitted to harassing and molesting these women. Why bother to take his deposition?  He’s already said, ‘I did it, I did it, I did it.’ Everyone has asked him to resign.”

What will it take to get Filner out of city hall?

“Probably a deal of some sort,” said Carl P. Luna, political science professor at San Diego Mesa College in an email exchange when the alleged victim count was still in single digits.  In return for Filner quitting, Luna said, the city would foot some of his legal costs, and the plaintiff or plaintiffs would “agree to settle for a sum that doesn’t leave Filner destitute in his retirement. Short of that there is no up side to resignation.”