The two major-party candidates running for governor in Virginia are both practicing Catholics. But when it comes to the contentious issue of abortion, they stand on opposite ends of the spectrum.

Republican Ken Cuccinelli opposes abortion in almost all circumstances — including rape and incest. He makes an exception when the life of the mother is endangered.

Democrat Terry McAuliffe supports most Virginia laws that prohibit third-trimester abortions except to protect the life or health of the mother. But he opposes further restrictions and says he supports a repeal of mandatory ultrasounds before abortions.

In a state considered one of the most antiabortion in the nation in terms of state laws restricting the practice, the issue has often been front and center as national antiabortion and abortion rights groups spend heavily on harsh ads.

On the campaign trail, Cuccinelli hasn’t talked as much about abortion as has McAuliffe, who has argued repeatedly that the issue is emblematic of what he characterizes as Cuccinelli’s extremism. Cuccinelli, in turn, has accused McAuliffe of distorting his views, and he has called McAuliffe the extremist for his abortion-rights stance.

The differences between the candidates on abortion and reproductive health-care issues appear to be resonating, particularly among women, who make up more than half of registered voters.

Polls are showing a wide gender gap in McAuliffe’s favor. In a Washington Post poll taken last month, for example, female voters preferred McAuliffe by a 24-point margin.

This has led abortion rights groups to conclude that if McAuliffe wins, it will be because of female voters.

“I think he will owe his victory to the women of Virginia,” said Tarina Keene, executive director of NARAL Pro-Choice Virginia, which has taken part in a “Stop Ken” campaign. “Women who want to own their own bodies. Who want to be able to make their own reproductive health-care decisions. They certainly want him to stand strong.”

Antiabortion groups say that’s exactly what they fear.

“If we hold a pro-life majority in the House of Delegates and perhaps gain more pro-life seats in the Senate, I see almost a stalemate of activity,” said Olivia Gans Turner, president of the Virginia Society for Human Life, whose political-action committee has endorsed Cuccinelli. “Terry McAuliffe would put up a roadblock for passage of pro-life bills. It means we’d lose four years providing protection to the most innocent among us.”

A number of relatively new laws in the state have helped reignite the discord over abortion and reproductive rights.

Last year, Virginia started requiring women seeking abortions to have ultrasounds.

This year, the state enacted a provision that bars insurers operating under the new health-care law from offering abortion coverage.

And the Virginia Board of Health has imposed a new building code on the state’s abortion clinics, including stricter standards for such things as hallway widths and the number of parking spaces. Some providers say costly renovations, mandated in the name of patient health and safety, will put them out of business. When the board decided to grandfather in existing clinics, Cuccinelli said that the board had exceeded its authority and that the attorney general’s office would not defend board members if any lawsuits. The board reversed its decision.

McAuliffe has said he supports repealing the ultrasound mandate. He opposed the abortion insurance ban that will have the effect of preventing anyone participating in federal health exchange from buying abortion coverage with her own money. And he has vowed to make the new clinic regulations less onerous.

“Terry will make appointments in consultation with his Secretary of Health and the medical community,” his campaign spokesman, Josh Schwerin, said in an e-mail, adding that the board’s decisions should be “based on sound medical recommendations, not ideological agendas.”

McAuliffe’s opposition to the abortion insurance ban has drawn particular ire from Cuccinelli and antiabortion groups, leading them to portray him as a pro-abortion radical who has distorted Cuccinelli’s record and positions.

“The only candidate in the race with an extreme view on abortion is Terry McAuliffe,” said Richard Cullen, communications director for the Cuccinelli campaign. “He supports taxpayer-funded abortion up until the moment of birth.”

McAuliffe’s campaign calls the accusation inaccurate.

“Virginia doesn’t allow taxpayer funding of abortion except in some extreme circumstances, and Terry would support keeping existing Virginia law and trusts women to make their own health-care decisions with their doctors,” Schwerin said. “In contrast, Ken Cuccinelli has said he wants to make abortion illegal even in the cases of rape, incest or to protect the health of the woman.”

The McAuliffe campaign has worked hard to paint Cuccinelli as out of the mainstream, pointing up the Republican’s long record of backing abortion restrictions.

A particular focus has been a proposal that Cuccinelli co-sponsored as a state senator in 2007, one that sought to bestow legal rights “from the moment of fertilization.” The American Congress of Obstetricians and Gynecologists said last year that such language could provide an opening for bans on common forms of birth control, particularly the pill and the intrauterine devise, which prevent a fertilized egg from implanting. McAuliffe ads featuring a ring of birth-control pills have suggested that Cuccinelli will outlaw the pill, something Cuccinelli has dismissed as “patently false.”

“You can’t block people from getting contraception, and we have no intention of doing that. I’ve never tried to do that, and I’m just not going to,” he has said.

Antiabortion groups accuse McAuliffe of hypocrisy and lying for claiming to be in favor of abortion rights while supporting state laws on abortion.

“Virginia has a whole host of laws he very clearly doesn’t support,” said Marjorie Dannenfelser, president of the Susan B. Anthony List, which has spent heavily on ads attacking McAuliffe’s positions. “I don’t know that he knows what Virginia law is.”

If McAuliffe has been vague on the specifics of what he would do on abortion if he wins, his supporters are confident that he will be a bulwark for abortion rights in an antiabortion state.

“He has said publicly, many times, that he will stand as a brick wall to protect women’s rights,” said state Sen. Barbara A. Favola (D), chairwoman of the Women’s Reproductive Health Caucus. “Given the choices we have, he has given voters enough comfort to realize he is not going to sign into law anything that further restricts women’s access to health-care services. It gives me comfort that he is going to protect my constitutional rights.”