WASHINGTON — Obama administration officials insisted Wednesday that the president's commitment to contraceptive access for women is "absolutely firm," even as Republicans from Capitol Hill to the presidential campaign trail assailed the policy as an attack on religious liberty.

Republicans seized on a call from Roman Catholic bishops, who in recent weeks have asked parishioners to object to a federal rule requiring religious-based institutions, such as Catholic hospitals and universities, to provide contraceptives as part of their employee health-care package, even though contraception violates Catholic teachings.

A new law taking effect this year requires most private insurers to pay for birth control. Religious groups have been given an extra year to comply.

At the White House, press secretary Jay Carney said the administration wants all American women — no matter where they work — to have access to the same health-care coverage and the same preventive-care services. That includes contraception without a co-payment.

"We want to work with all of these organizations to implement this policy in a way that is as sensitive to their concerns as possible," Carney said. "But let's be clear: The president is committed to ensuring that women have access to contraception without paying any extra costs, no matter where they work."

Political fight

On Capitol Hill, House Speaker John Boehner, R-Ohio, delivered a rare floor speech vowing a repeal. He and his Republican counterparts in the Senate called it an "assault on religious liberty."

"In imposing this requirement, the federal government has drifted dangerously beyond its constitutional boundaries, encroaching on religious freedom," said Boehner, a practicing Catholic.

He said that he had asked the chairman of the House Energy and Commerce Committee, which is at the center of the Republican fight against the health-care law, to draft legislation blocking the rule. Kathleen Sebelius, the secretary of health and human services, will be questioned about the new rule at a hearing March 1, Republicans said.

Some Democrats also are uneasy about the rule. Underscoring the potential for a political backlash, one of Obama's most high-profile allies joined those criticizing the provision. Former Virginia Gov. Tim Kaine, once the president's hand-picked Democratic Party chairman and now running for Senate in a state considered crucial for Obama's re-election, said the administration "made a bad decision in not allowing a broad enough religious employer exemption" in the rule, according to a transcript of his remarks.

The administration scrambled to contain the controversy — and cast the debate not as one about religious freedom, but one about access to affordable preventive care for women. Democratic women also jumped to the defense of the policy, calling the Republican efforts to repeal the birth-control-coverage requirement an "aggressive and misleading campaign to deny" health care to women.

"Those now attacking the new health-coverage requirement claim it is an assault on religious liberty, but the opposite is true," wrote Sens. Jeanne Shaheen of New Hampshire, Barbara Boxer of California and Patty Murray of Washington.

"Religious freedom means that Catholic women who want to follow their church's doctrine can do so, avoiding the use of contraception in any form," the senators wrote. "But the millions of American women who choose to use contraception should not be forced to follow religious doctrine, whether Catholic or non-Catholic."

A survey released this week by the nonprofit, nonpartisan Public Religion Research Institute found that 49 percent of Americans say that religiously affiliated colleges and hospitals should be required to provide their employees with health-care plans that cover contraception or birth control at no cost. Forty-six percent said they shouldn't have to provide such coverage.

But 52 percent of Catholics said religious institutions should provide coverage that includes contraception. The numbers were even higher among young people: 58 percent of people ages 18 to 29 said religious institutions should provide health-care plans that include contraception coverage. Women were "significantly more likely" than men to agree.

Democrats suggest there's heightened awareness about politicizing women's health care after the Susan G. Komen for the Cure breast-cancer charity's decision to end — and restore, after an outcry — grants for breast-cancer detection to Planned Parenthood.

"Women in this country are tired of being treated like a political football by Republicans in Congress who have tried continually and are continuing to try to take away their benefits, to take away their rights," Boxer said Wednesday at a news conference.

She also pointed out that for about 15 percent of women, birth-control pills are used to treat endometriosis and other conditions.

"It's medicine and women deserve their medicine," she said.

Policies for women

Carney dismissed any political calculations, saying Obama was "focused on putting in place the right policies for women across the country. He added that the administration is prepared to work with religious organizations that say the new provision would require them to violate their conscience.

He also said the White House was sensitive to the religious concerns and had included a process for further talks and an exemption for churches and houses of worship.

"From the beginning, we understood the sensitivity of this," Carney said. "That is why we sought the balance that we did in the policy itself, why churches and houses of worship are exempted and why this transition period was a part of the rule and why we're having these conversations."

On the Republican presidential campaign trail, former Massachusetts Gov. Mitt Romney accused Obama of an "assault on religion," and Rick Santorum on Fox News accused the president of overstepping his constitutional authority.

"He is trampling on the most sacred right, the freedom of conscience," Santorum said, predicting the administration would backtrack. "I predict they're going to fold their tent on this one."

Carney called Romney an "odd messenger," because the services that would be provided under the rule are the same provided in Massachusetts when Romney was governor, including contraception and a religious exemption for houses of worship, churches and parochial schools.

He called it "ironic that Mitt Romney is criticizing the president for pursuing a policy that's virtually identical to the one that was in place when he was governor of Massachusetts."

Insurers in 28 states, including Washington, are required to cover contraceptives.

Material from The Washington Post, The Associated Press and The New York Times is included in this report.