Accusations follow spate of others from former aides and acquaintances which have triggered a lawsuit against Bob Filner

Two more women have come forward to accuse San Diego mayor Bob Filner of sexual harassment, bringing the number to 13 and piling pressure on him to resign.

Eldonna Fernandez and Gerri Tindley said Filner posed as a champion of women in the military but abused his power and their trust by making unwanted sexual advances.

CNN on Wednesday played a voicemail message he left for Fernandez after an August 2012 meeting of the National Women's Veterans Association of America (NWVAA): "Hi, it's your newly favourite congressman, Bob Filner. You know, the one who fell in love with you at your last speech." He invited her on a date. "I don't want to wait 'til you come back to have dinner with you."

At the same event Tindley, who had spoken of being raped during her time in the army, said Filner made her feel "weird" by accosting her on a sofa when they were alone. "He got as close as he could to me. His jacket was touching my jacket. I was bent down. He was bent down with me, rubbing like he cared, like he was consoling me." Tindley said she almost fell off the sofa trying to move away from him.

The allegations follow a spate of others from former aides and acquaintances – including forcible kissing, groping, manhandling and lewd comments – which have triggered a sexual harassment lawsuit and demands for the 70-year-old divorced mayor to quit.

Filner, a Democrat, did not immediately respond to the latest accusations.

Earlier this week he started a two-week intensive therapy course to correct behaviour which he admitted had been at times inappropriate. He has reportedly submitted a doctor's note saying he will not be at an August 9 deposition to respond to the lawsuit, which was filed by his former communications director, Irene McCormack Jackson.

A veteran politician who served ten terms as a congressman before being elected mayor last year, he has rebuffed calls to step down.

The latest accusations may prove especially damaging because there is a recording – Fernandez said she had deleted the voicemail but retrieved it after allegations started surfacing last month – and because of the circumstances.

The alleged victims were highlighting sexual assaults in the military when Filner, claiming solidarity, made his alleged advances.

Fernandez, a retired master sergeant from the Air Force, said she was raped three times during her 23-year service. Her talk at the NWVAA event in San Diego was part of a campaign to bring such abuses to light.

After her speech she exchanged business cards with the then-congressman, she told CNN. "He looks at my card. He looks at me. He says, 'Fernandez. Are you married? Do you have a husband?' Very quick, very direct. I said, 'No, I'm divorced.' 'Well, you're beautiful, and I can't take my eyes off you, and I want to take you to dinner.' I was really shocked and I was like, 'Uh, OK,'" Fernandez said. Filner followed up with the voicemail message, which Fernandez said she ignored.

Tindley, who bore a son from her rape, told CNN she she felt powerless when cornered on the sofa. "What am I gonna say? You're a congressman. What am I gonna say to you? What am I gonna say to his man? Can he destroy my life, can he stop me from moving forward?"

At least six other members of the NWVAA have made similar accusations against the mayor.

Michelle Tyler, a nurse who cares for a wounded marine, told a news conference on Tuesday that at a meeting in June the mayor tried to trade his help for the marine for sexual favours from Tyler.

© Guardian News and Media 2013

[Embattled San Diego Mayor Bob Filner at a Board of Port Commissioners meeting in January, 2013. Photo: Flickr user Port of San Diego, creative commons licensed.]