With Election Day less than three weeks away, the two major party candidates in Maine’s U.S. Senate race have been competing for specific endorsements as they try to win the support of voters.

Over the past several days, the campaigns of Sen. Susan Collins and U.S. Rep Tom Allen have announced dueling endorsements by the national and Maine chapters of the League of Conservation Voters.

And last week, Planned Parenthood announced it is endorsing Allen even though it had endorsed Collins in a previous election.

On the environmental front, the Allen campaign on Oct. 10 announced the support of officials with the Maine League of Conservation Voters, among other Maine environmental advocates.

But on Wednesday, the national League of Conservation Voters announced it was supporting Collins.

Tony Massaro, senior vice president for the national league, said Wednesday during a press conference call that the competing endorsements do not represent a split within the league. State chapters do not endorse candidates in federal elections, he said, and individuals who hold positions with the league are free to support whomever they want.

“We are quite comfortable with that,” Massaro said. “We fully expect them to take positions.”

He said the endorsement of Collins was a reflection of her voting record in the Senate, not of Allen’s voting record. Collins is the only Republican Senate candidate the league is endorsing this year.

“Congressman Allen is absolutely a friend,” Massaro said. “No one should take this as a sign that the league is diminishing anything Tom Allen has done. This is an endorsement that is about Susan Collins.”

Officials said they picked Collins because of her leadership on global warming and preventing oil drilling in the Arctic National Wildlife Refuge in Alaska.

“She just doesn’t just vote right, she leads on these issues,” Massaro said. “She expends precious political capital on these issues. That is a rarity in Washington D.C.”

Collins welcomed the support, calling the league the nation’s foremost advocacy environmental coalition.

According to the Allen campaign, Allen has been endorsed by 40 former and current environmental advocacy leaders in Maine. That includes six board members of the Maine League of Conservation Voters.

He has a higher lifetime rating from the league – 93 percent compared with Collins’ 68 percent – and has co-sponsored aggressive legislation to reverse climate change while Collins has supported budgets that slash funding for environmental protections, the campaign said in a prepared statement.

“Tom has been a thoughtful and strong advocate for a range of key environmental issues during his tenure in Congress,” Ellen Baum, board vice president of the Maine league, said in the statement. “I look forward to the commitment and seriousness that he will bring to the Senate.”

The tug-of-war over which candidate has the best environmental credentials follows an announcement that Allen has been endorsed by Planned Parenthood, which endorsed Collins six years ago.

The national women’s health care education and advocacy group said in an Oct. 8 press release it was supporting Allen because of President Bush’s appointment of anti-abortion judges to the federal bench. Collins, who has a pro-choice voting record, was endorsed by the group in 2002, when she was re-elected over challenger Chellie Pingree.

Chris Quint, public affairs director for Planned Parenthood of Northern New England Action Fund, said Tuesday that the group was unhappy with Collins’ support of Samuel Alito when he was appointed to the U.S. Supreme Court in 2006, and her support of other anti-abortion federal judges.

Alito has a history of opposing women’s reproductive rights, according to Quint.

“What it came down to was the courts,” Quint said. “We appreciate that we’ve had Senator Collins these past two terms to stand up to her party.”

Allen, Quint said, has a 100 percent vote rating from Planned Parenthood.

“We look forward to doing whatever we can to ensure the people of this state know who they can trust to protect their rights, protect our courts, and protect the health and safety of all Mainers,” Quint said in a prepared statement.

Allen said he was happy to get Planned Parenthood’s endorsement. By saying she is pro-choice but by supporting Alito’s nomination, Collins is trying to please people on both sides of the abortion debate, he said.

“I think her support for Sam Alito and a whole host of other judicial nominees to the [federal bench] indicates pretty clearly that she’s trying to have it both ways,” Allen said. “You appeal to one group with your legislative record and appeal to another group with your votes on judicial nominees.”

The Collins campaign, however, accused Planned Parenthood of playing partisan politics by endorsing Allen.

Kevin Kelley, Collins’ campaign spokesman, said Tuesday in an e-mail that Collins has a 93 percent vote rating from the group.

“It’s unfortunate that Planned Parenthood’s endorsement process has become so partisan,” Kelley wrote.

In a recent interview with Associated Press, Collins defended her support for Alito.

“I also have a solid pro-choice voting record,” Collins told AP. “I do not, however, apply a litmus test for whether an individual should serve on the Supreme Court … I have voted against more of President Bush’s judicial nominees than I did President Clinton’s.”