Like many Egyptian women, 31-year-old activist Dalia Ziada took to the street in early 2011 to join the protest movement that deposed dictator Hosni Mubarak. Afterward, she ran as a candidate in the country’s first open parliamentary elections, facing down death threats from religious extremists. Since the Muslim Brotherhood has come to dominate Egypt’s politics, she has fought hard against what she sees as the Islamist group’s attempts to roll back women’s rights.

So when Ziada heard that the Brotherhood had issued a rebuttal to a recently proposed U.N. declaration condemning violence against women, her reaction was defiant. “I’m not scared of them,” she said. “The women’s rights movement in Egypt is very strong.”

The latest showdown between the Brotherhood and Egypt’s activists began on Wednesday, when the former slammed the U.N. proposal as a step that would result in “the complete disintegration of Egyptian society.” It went on to outline a litany of objections, including to ideas such as “Granting girls full sexual freedom,” “Giving wives full rights to file legal complaints against husbands accusing them of rape or sexual harassment,” “Equal inheritance,” “Full equality in marriage legislation,” “Removing the authority of divorce from husbands,” and “Cancelling the need for a husband’s consent in matters like: travel, work, or use of contraception.”

“I don’t think the government will be able to change in any way what we have been able to achieve so far with respect to women’s rights.”

The Brotherhood’s statement, which seemed to confirm hardline stances on the role of women that it has espoused for decades, caused a firestorm, with the group’s opponents saying they feared it will try to push such views into law. These issues had already come up after the parliamentary polls last year, when some newly elected Islamists discussed pushing for more conservative laws on issues such as female genital mutilation, travel restrictions on women and a woman’s right to divorce. Though the Brotherhood and other Islamist groups won nearly 70 percent of the vote, they met with fierce resistance from women’s rights groups and others. “We stood up and said, ’we will not allow it,’” said Ziada, who remains optimistic about the fight. “I don’t think the government will be able to change in any way what we have been able to achieve so far with respect to women’s rights.”

Women’s rights activists say they are a powerful force to be reckoned with, pulling together a broad spectrum of activist groups. “All of us are united now around one thing: women’s rights,” says Inas Mekkawy, an advocate. “Women will not allow the Muslim Brotherhood to accomplish any of these plans.”

A similar attitude was on display last week during a march in Cairo on International Women’s Day. The crowd, made up of both men and women, flew banners of heroines of Egypt’s past, from nuclear scientist Sameera Moussa to Hatshepsut, the legendary pharaoh who ruled in the 15^th Century B.C. One popular chant went: “A woman’s voice is a revolution.”

But Mekkawy also noted that the new constitution penned by Islamists late last year – and passed in a December referendum – makes no mention of women’s rights. And advocates worry about what might happen if Islamists again sweep the next parliamentary elections, which could be held as early as this spring. (The previous parliament was dissolved by a court ruling last summer.)

Elhan Abdelhamid, a professor at Cairo University and member of the National Council for Women, said that while big legislative battles over women’s rights would likely generate media attention and train a spotlight on the issues, additional threats lurk under the radar. For example, she said that Islamists are pushing to rewrite school textbooks to reflect their conservative views on women, and have even been pressuring teachers to fall into line. “They are trying to change society from the inside,” she said.

Mike Giglio is a correspondent at Newsweek.