Planned Parenthood’s president, Cecile Richards, gave a damning verdict on the Republicans’ healthcare bill to repeal and replace the Affordable Care Act on Thursday, saying: “Being a woman is going to be now a pre-existing condition in this country.”

Speaking hours after the American Health Care Act was narrowly passed in the House of Representatives, the activist – who is a key figure in the campaign for American women’s health and reproductive rights – received a standing ovation as she arrived on stage to address a packed audience at the New School in New York as part of PEN America’s World Voices Festival.

Richards said the bill, which won by a margin of just four votes, was “jammed through” without proper scrutiny or debate, adding: “To say it’s unpopular is really an understatement.”

Opening the talk, Richards tried to strike an optimistic tone by saying to cheers and applause that the delay to the bill – which failed to win sufficient support in March – proved that “the resistance is working”.

However, she went on to describe the damage that the bill, which she described as “a vampire resurrected”, could go on to cause if it gets past the Senate. Preventing that outcome, she said, was now the key focus for campaigners’ energies.

She told the audience: “Today, of course, for those of you who have been blissfully off of Twitter, the House of Representatives jammed through a bill that really very few members of Congress, I think, had read. Certainly the Congressional Budget Office hadn’t even scored in terms of its impact – both fiscal impact and impact on folks.”

She added: “There’s a lot of things in the bill, we can talk about them, but of course one of the things that has been foremost on the mind of some of the leaders and Speaker [Paul] Ryan was ending access to Planned Parenthood for women on, patients on Medicaid.

“That means millions of folks who come to us for cancer screenings and for family planning, particularly in medically underserved areas, will no longer be able to go to Planned Parenthood for that care.”

She said based on the evidence she has seen in her home state, Texas – where more than half the abortion clinics have closed – the effects of the new healthcare plan would be “devastating”.

“The impact is immediate on women and particularly women on low income, women of color,” she added.

Citing figures that estimate 24 million people will lose their health insurance coverage under the bill, she talked about its other possible implications.

Richards said the equity “we fought for so hard under President Obama” had been “thrown out”, gender ratings enabling insurance companies to charge women more would return, and it would be more difficult for women to have access to maternity coverage and family planning.

“Supposedly the pro-family party just passed a bill that will basically make it harder to not get pregnant, harder to have a healthy pregnancy and harder to raise a child,” she added.

Although Richards said the Senate was “a place where cooler heads prevail”, where she claimed the bill is “wildly unpopular”, she feared the Senate majority leader, Mitch McConnell, would “try to get it through” regardless.

She urged opponents of the bill to “tell the story of what happened”, adding: “The more this gets out there, the more people hear about it, the less popular it is and the more people that, when these guys go back home, because of course they’re mainly guys, they go back home and they have to deal with a lot of women in pink pussy hats, Planned Parenthood signs and patients telling their stories, and they don’t like that.”

The event, which had been scheduled long before the bill’s outcome was known, featured a discussion between Richards and the PEN America executive director, Suzanne Nossel, about the body politic.