The state’s leading antiabortion group said Thursday that it plans to support Senator Scott Brown’s reelection campaign, potentially undercutting the Republican’s effort this week to distance himself from his party’s support for strict antiabortion measures.

“We consider him a senator who votes prolife,’’ said Anne Fox, president of the Massachusetts Citizens for Life. “We have to take his word for it when he says he is prochoice. But what we’re looking for is someone who votes prolife, and he does.’’

Brown said he would not reject the backing of Massachusetts Citizens for Life but reiterated that he considers himself a supporter of abortion rights.


“There are people of good will on both sides of the abortion issue, and Senator Brown welcomes their support, but he is prochoice and his record going back many years reflects that,’’ said Colin Reed, a Brown spokesman.

Still, Brown received the backing of Massachusetts Citizens for Life in his 2010 run for Senate and has sided with the National Right to Life Committee on four of its five key votes since he arrived in Washington, earning him an 80 percent approval rating.

The issue of abortion has suddenly become prominent in Brown’s race against Democrat Elizabeth Warren — and in races across the country — since Missouri Senate candidate Todd Akin said Sunday that “legitimate rape’’ victims can somehow prevent pregnancies.

Brown has seized on Akin’s remarks to bolster his abortion-rights credentials. He was the first Senate Republican to call for Akin to abandon his campaign, and he urged his party “to recognize in its platform that you can be pro-choice and still be a good Republican.’’

On Wednesday, in response to a reporter’s question over whether he would pledge to “never vote in the Senate to curb women’s reproductive rights,’’ Brown said he would agree.

“I have a long record of this already,’’ he said. “I’ll promise that. I’ve already been on record on that.’’


Brown’s record, however, has at times angered abortion rights groups, several of which have endorsed Warren.

In the US Senate, he cosponsored the Blunt Amendment, which would allow health plans and employers to refuse to provide or pay for services such as abortion which they oppose on religious or moral grounds.

The National Right to Life Committee credited Brown for that bill and for voting to repeal President Obama’s health care law, blocking funding for the law, and opposing the Disclose Act, which would require independent political groups to disclose the names of donors who give more than $10,000. The committee considers the bill an attack on its First Amendment rights.

Brown’s votes against the health care law and the Disclose Act were driven by concerns unrelated to abortion.

Brown also occasionally sided with antiabortion activists when he was in the state Legislature. In 2005, he sought to allow doctors and nurses to opt out of offering emergency contraception to rape victims if the health care workers had religious objections. Brown later voted for the bill without his changes, meaning doctors and nurses would be required to offer emergency contraception, regardless of their beliefs.

In addition, Brown cosponsored the Women’s Right to Know Act, which would require women to wait 24 hours before having an abortion and to review pictures and information detailing the development of their fetus.

But Brown has also taken votes in the state Senate and the US Senate that were applauded by abortion-rights supporters. In 2007, he voted to create a 35-foot buffer zone to keep protesters away from abortion clinics. In 2012, he voted to repeal a law that required women in the military who are victims of rape to pay for abortions at military facilities. He also opposed an effort to cut off federal funding for Planned Parenthood.


Raymond L. Flynn, the former Boston mayor who is also nationally known as an antiabortion activist, said that while Brown’s record on abortion is “mixed . . . he would be more prolife than his opponent.’’

“His heart is prolife,’’ said Flynn, who has endorsed Brown.

But Brown’s campaign countered that characterization, releasing a statement Thursday from Kerry Healey, a former lieutenant governor.

“Scott Brown is prochoice, and has voted that way in both the State House and the US Senate,’’ Healey said. “He stands in the mold of other New England Republicans like myself who are fiscally conservative and socially moderate.’’

Warren, however, has seized on Brown’s backing within the antiabortion movement to question the depth of his support for abortion rights.

“It is not enough to say the right thing some of the time; women need a senator who will be a leader all of the time,’’ Mindy Myers, Warren’s campaign manager, said in a statement Thursday.

Fox, the Citizens for Life leader, said Brown deserves credit for backing strong parental consent laws and opposing the procedure that opponents call partial birth abortion, among other stances.

She said she met with Brown last month and urged him to support a bill that would ban abortions after 20 weeks and would only apply to clinics in the District of Columbia. Brown did not rule it out and promised to study the bill, she said.

Fox said the group does not consider its support for Brown a formal endorsement because of Brown’s stated support for legalized abortion.But she said the group would urge its members to vote for the senator and enlist volunteers for his campaign.

In Brown’s 2010 race against Democrat Martha Coakley, the group ran a radio ad for Brown and recruited volunteers who made 460,000 phone calls for Brown, Fox said.