Several Republican candidates for Senate have embraced an unorthodox issue as the midterm election approaches — support for over-the-counter birth control pills.

At least three GOP hopefuls have spoken during the summer in favor of allowing certain types of contraception to be sold without a prescription. Rep. Cory Gardner (R-Colo.), who is challenging incumbent Sen. Mark Udall (D), on Tuesday released a television ad in which he tells a room full of nodding women, “I believe the pill ought to be available over the counter, around the clock, without a prescription. Cheaper and easier for you.”

The ad followed similar remarks by Ed Gillespie, a Republican running for Senate in Virginia, and Mike McFadden, who is challenging Sen. Al Franken (D) in Minnesota.

Their endorsement of easier, drug-store access to contraceptive medications marks a new front in an ongoing political battle over women— one that has seen Democrats more often gain the upper hand. This issue could give GOP candidates a way to push back against the perception that their party holds outdated notions about women and sex.

“If anything, it probably defangs this increasingly concerted effort by the political left to caricature male Republican politicians as anti-woman, anti-birth control, anti-rainbows and sunshine,” said Kellyanne Conway, a Republican pollster who specializes in women voters.

While some countries do allow over-the-counter sales of contraceptive medications, and professional groups such as the American Congress of Obstetricians and Gynecologists have said they are safe enough to sell in U.S. drug stores, the Food and Drug Administration has not approved the medications to be sold without permission from a doctor.

Last year, the agency approved over-the-counter sales of the so-called “morning-after pill” without age restriction. Also known as an “emergency contraceptive,” the drug can prevent pregnancy if taken shortly after sexual intercourse. But that change only took place after a protracted legal battle.

While liberalizing the policy on birth control pills would be welcomed by reproductive rights groups, the groups say the pills are expensive if purchased out-of-pocket, as much as $600 for a year’s course. They say such a policy would not help women buy a type of birth control that is rapidly gaining popularity — the intrauterine device, or IUD.

IUDs, reported to be more effective than pills but more expensive, are opposed by many Republicans who consider them abortion-inducing because the devices can interfere with pregnancy after an egg has been fertilized.

On Monday, the political action arm of Planned Parenthood issued a statement accusing Gardner and other Republicans of trying to “muddy the waters around their unpopular positions on women’s health,” and called the endorsement of over-the-counter birth control pills an “empty gesture.”

Planned Parenthood is stressing its support for changes ushered in by the health-care law, which expanded access to private health insurance and requires plans to cover all forms of contraceptives approved by the FDA, including the IUD.

Strategists say the GOP candidates’ support for over-the counter birth control pills gives them a way to state unequivocally that they are not opposed to all forms of contraception.

The issue is not entirely new for Republicans.

Louisiana Gov. Bobby Jindal endorsed the idea in a 2012 Wall Street Journal op-ed in which he argued that “big government” forces women to go to the doctor before getting birth control bills, and pharmaceutical companies make more money by requiring prescriptions. He made clear that, though he opposed abortion on religious grounds, he supports the rights of adults to obtain birth control.

“I believe that we have been stupid to let the Democrats demagogue the contraceptives issue and pretend . . . that Republicans are somehow against birth control,” he wrote.

The issue is grabbing attention at a time when Republican candidates have taken heat over their support of so-called “personhood” bills, which would give fetuses the same rights as those who are born. Such bills could render some forms of contraceptives illegal, including, for instance, IUDs.

The problem is particularly acute for Gardner, who had supported such legislation in the past but disavowed his position in an interview with the Denver Post earlier this year. “This was a bad idea driven by good intentions,” he told the newspaper.

In a press release Tuesday, Udall’s campaign called Gardner’s ad “jaw-dropping.” Spokeswoman Kristin Lynch accused Gardner of doing “anything to hide his backwards agenda for Colorado women.” The campaign noted that Gardner is still listed as a co-sponsor for a federal “personhood” bill.

In July, an NBC News/Marist College poll showed that 70 percent of Colorado residents would be less likely to support a candidate who supported restrictions on contraception, and 67 percent would be less likely to support a candidate who supported restrictions on abortion.

The GOP candidates also are facing Democratic attacks over their support for a Supreme Court decision this year in the Hobby Lobby case. That decision allowed certain companies to gain an exemption on religious grounds from an Obama administration rule that employers must provide their workers with free birth control as part of their employee insurance policies.

Staff writer Jaime Fuller contributed to this report.