Hartford — The head of a leading national abortion-rights group said at a campaign rally Thursday for Democratic U.S. Senate candidate Chris Murphy that his Republican opponent is a threat to legal abortion in this country.

"Linda McMahon is not pro-choice," said Nancy Keenan, president of NARAL Pro-Choice America. "You see, you cannot be pro-choice when you support bosses who can deny women their birth control coverage for their women employees. You are not pro-choice when you will not stand up and unequivocally support freedom and privacy and Roe v. Wade."

Keenan referred to McMahon's stated support for the "Blunt amendment," a Republican proposal in Congress that would have allowed employers with moral objections to opt out of providing workers certain coverage in the 2010 Affordable Care Act, such as birth control.

McMahon says she is pro-choice on abortion rights and supports access to contraception. She would have supported the Blunt amendment because "it was about religious freedom, over-regulation of businesses and the government imposing its will on individual citizens."

Keenan was one of five speakers at an afternoon "Women's Health" news conference in Murphy's Hartford campaign office, including the candidate and his wife, Cathy Holahan, a former board president of NARAL's Connecticut chapter.

In his remarks, Murphy vowed to oppose any U.S. Supreme Court nominee who would overturn the Roe v. Wade decision that legalized abortion.

"That is a litmus test for me," Murphy said. "I think this issue is so important that we need to use it as a condition for elevation to the Supreme Court."

McMahon's campaign said McMahon has been unwavering in her support of abortion rights.

"Linda McMahon has been clear from the beginning of her campaign that she is a pro-choice candidate, even though her position puts her at odds with her party," said Kathy McShane, chairman of the Women for Linda coalition. "I respect that Linda is an independent thinker who will not always agree with her party; instead, she will do what is right and what reflects the viewpoints of the people she represents."

The two candidates met Thursday night for a debate at the University of Connecticut.

j.reindl@theday.com