He said women in Iran were free to express their opinions, even if he and others did not agree with some of their views.
But the activists question that freedom. Another member of the "Million Signatures Campaign", who declined to be named because of the sensitivity of the issue, said about 40 people had been temporarily detained in connection with the drive.
"We are under increased pressure," she said. "You have a lot of resistance to women's rights."
One of those held was Jelveh Javaheri, who was in Tehran's Evin jail for a month accused of spreading propaganda against the Islamic system, before being released on bail in early January, with fellow rights campaigner Maryam Hosseinkhah.
Javaheri's husband, Kaveh Mozafari, is proud of her: "I'm glad she believes (in her cause) so much that she goes to jail for it," he said.
A U.S.-based rights group said in December the charges against the two women were politically motivated.
"There seems to be no end in sight to the Iranian government's persecution of women's rights activists," said Sarah Leah Whitson, Middle East director at Human Rights Watch based in New York.
OUT IN THE OPEN
Although women are legally entitled to hold most jobs, Iran remains dominated by men. In recent years women have started to work in the police and fire departments and there are female members of parliament, but they cannot run for president or become judges.
The activists say it is difficult for women to get a divorce. They criticise inheritance laws as unjust, also the fact a woman's court testimony is worth half that of a man's.
Campaigners point to some positive changes in society, saying most university students these days are women. However, they also say a proposal now before parliament would make it easier for a man to take a second wife.
"Women's status has changed considerably for the better," said activist Sara Loghmani. "The law is the problem."
She and others declined to say how many signatures they had collected so far - but they insist the message is being spread despite minimal coverage in the domestic media.
"The campaign has brought the issue out in the open," campaigner Sussan Tahmasebi said. "You have grandmothers, mothers and daughters working on this side by side."
But many people are still not aware of the petition.
"I've never heard about it. What is it?" said 23-year-old university student Yasaman, who only gave her first name.
Keshavarz is undeterred: "For me, prison demonstrated the righteousness of our cause," she said. "No, it hasn't stopped me, it hasn't frightened me."
