Health and Human Services Secretary Kathleen Sebelius is pictured before President Barack Obama signs an executive order directing the Food and Drug Administration to take steps to reduce drug shortages in the Oval Office at the White House. (Charles Dharapak/AP)

Republican lawmakers are objecting to the Department of Health and Human Services’ decision to deny an anti-human-trafficking grant to a Catholic group , a dispute that reflects deep divisions over access to abortion and birth control.

In late September, HHS ended funding to the U.S. Conference of Catholic Bishops to help victims of trafficking, or modern-day slavery. The church group had overseen nationwide services to victims since 2006 but was denied a new grant in favor of three other groups.

The bishops organization, in keeping with the church’s teachings, had refused to refer trafficking victims for contraceptives or abortion. HHS officials have said they made a policy decision to award the grants to agencies that would refer women for those services.

In recent letters to HHS Secretary Kathleen Sebelius, more than 30 Republican lawmakers said the decision was unfair to the Catholic group and might violate federal laws banning discrimination based on religion. Two of the letters are seeking internal HHS documents relating to the decision and one, sent Monday by Rep. Darrell Issa (Calif.), said his investigative committee may issue subpoenas if HHS doesn’t comply.

“We’re talking about a Catholic group with a superior track record that was pushed aside to promote the abortion agenda,” said Rep. Christopher H. Smith (N.J.), who wrote the 2000 law that triggered the U.S. government’s war on human trafficking.

HHS officials said Friday that they will respond to the letters from Congress but not through the media. Richard Sorian, the agency’s assistant secretary for public affairs, said HHS is “fully confident that the organizations best suited to provide comprehensive case management to victims of trafficking were awarded the grants for these services.”

“The health and ability of these victims to retake control over their own lives is our sole concern in awarding these grants,” he said. HHS officials have previously denied any anti-Catholic bias and said that since the mid-1990s, Catholic groups have received at least $800 million in HHS funding to provide social services, including $348 million to the bishops conference.

The dispute is one of several between the Obama administration and some Catholic groups over policy issues, including a proposed HHS mandate that private insurers provide women with contraceptives for free.

Senior HHS officials awarded the new grants to the bishops’ competitors despite a recommendation from career staffers that the Catholic group be funded based on scores by an independent review board, according to federal officials and internal department documents.

That prompted a protest from some HHS staffers, who said that the process was unfair and politicized, people familiar with the process have said.

The $4.5 million in funding was awarded to three nonprofit groups: Heartland Human Care Services, Tapestri and the U.S. Committee for Refugees and Immigrants.

The applications of Tapestri and the U.S. Committee for Refugees and Immigrants had been scored significantly below the Catholic bishops’ application by the review panel, the sources said.

Sister Mary Ann Walsh, a spokeswoman for the bishops conference, said Friday that she welcomed the letters from Congress. “The more we look at this, the more concerned we are about it,” she said. “It appears the grant process was manipulated.”

One letter to Sebelius, by Republican Sens. Marco Rubio (Fla.), Roy Blunt (Mo.) and Kelly Ayotte (N.H.) and signed by 24 other senators, made a similar point. “The integrity and lawful administration of our federal grant process — particularly with respect to equal treatment of religious institutions — must not be compromised,” it said.