A debate about women's access to birth control is once again brewing in Washington. 

On Tuesday, Sen. Patty Murray, D-Wash., introduced the Affordability Is Access Act, which would require health insurance companies to cover birth control pills if they are offered in pharmacies without a prescription from a doctor.

"I believe strongly that women should be able to get the comprehensive health care they need, when they need it, without being charged extra, without asking permission and without politicians interfering," Murray said Tuesday in a call with reporters.

The proposal comes just weeks after a related bill, the Allowing Greater Access to Safe and Effective Contraception Act, was introduced by Republican Sens. Cory Gardner of Colorado and Kelly Ayotte of New Hampshire. It would incentivize drug companies to seek approval from the Food and Drug Administration so "routine-use contraceptives" could be sold over the counter.

Democrats including Murray – along with organizations like Planned Parenthood – came out strongly against the Republican bill, saying it would increase costs for women because they would now have to pay for previously covered forms of contraception out of pocket. Without insurance coverage, birth control pills can cost up to $600 a year, according to Planned Parenthood Action Fund.

But even though the Gardner-Ayotte bill doesn't specifically make provisions for insurance coverage, a Gardner spokesman says the Colorado senator also believes that insurance companies should be able to cover over-the-counter contraception.

"It's unfortunate that they have decided to bring partisanship to an issue that could have broad support on Capitol Hill, but we are pleased they are following our lead," the senator tells U.S. News in a statement.

President Barack Obama's health care law, the Affordable Care Act, already mandates that health insurance companies cover every form of prescribed, FDA-approved birth control for women without a copay. The American College of Obstetricians and Gynecologists has supported over-the-counter birth control pills since 2012, and also takes the position that they should be covered by health insurance.

The group and Planned Parenthood on Tuesday backed Murray's bill. 

"To be truly accessible, birth control must be affordable," said Cecile Richards, president of Planned Parenthood Action Fund.

The topic of over-the-counter birth control pills gained momentum during the 2014 midterm elections, particularly among Republicans. Half of all pregnancies are unplanned, and not all women have access to a birth control pill.

It isn't typical for over-the-counter drugs to be covered by health insurance, but some are. For example, Prilosec, a heartburn drug, sometimes can be paid for with insurance. Plan B, the so-called morning-after pill, also is supposed to be available over the counter and can be covered by health insurance under the health care law.

When Gardner was running for Senate, he wrote in The Denver Post that making birth control available over the counter would make the drugs cheaper and save women time and money by letting them avoid unnecessary doctor's appointments. Proponents also have argued that it isn't always convenient to see a doctor for birth control pills, and that a woman should be able to have easier access to them in case she runs out, is traveling or loses them.

A study published in February in the journal Contraception found that 21 percent of low-income women at risk for unintended pregnancy were very likely to use the pill if it was available over the counter. When covered by insurance, an additional 11 to 21 percent of low-income women would use it. The findings showed that this could decrease unintended pregnancies by as much as 25 percent.

Carrie Lukas, managing director of the right-leaning Independent Women's Forum, says there is no reason for the government to prevent someone from buying a drug unless there are significant safety concerns. "Women are perfectly capable of using this drug without a prescription," she says. "It makes sense for the government to get out of the way."

The organization, though, does not support forcing insurance companies to cover the costs. Instead, Lukas says, people should be able to choose whether they want to purchase a health plan that includes coverage for birth control.

"Proponents make it sound like if you oppose it then you are being anti-women or unsympathetic to those who have no incomes, but it's actually an enormous gift to drugmakers," she says. "They get to charge whatever they want and there is no incentive to control costs."

Some opponents, however, have concerns about offering the pill over-the-counter at all and without the guidance of a doctor. Dr. Donna Harrison, executive director for the American Association of Pro-Life Obstetricians and Gynecologists, says she is worried women would miss out on testing for sexually transmitted diseases if the pill was to be made so easily available.

She also expressed concern about teens getting access to birth control without a doctor's counseling and that young victims of trafficking would not be identified if not checked regularly.

"It takes the highest-risk women and separates them from medical care," she says.

Some women also have side effects from birth control, which can be mild and include spotting, nausea, weight gain or breast tenderness. These same side effects can be severe enough to make women want to switch prescriptions – something a doctor could guide them through.

But Dr. Mark DeFrancesco, president of the American College of Obstetricians and Gynecologists, doesn't think women will ignore their routine screenings if oral contraceptives were made more readily available.

"So many of our patients come to our offices for their annual exams, not to get contraception," he says.

Women who are uninsured and cannot see a doctor, he says, at least would be able to have access to contraception if it was available at a pharmacy.

"I think there are much more pluses involved than minuses," he says.