WASHINGTON (AP) — Senate Republicans pressed their fight Wednesday to bar federal aid to Planned Parenthood, but likely opposition from at least one GOP senator highlighted the long odds they face to prevail.

With a showdown Senate vote planned for early next week, Democrats stepped up their defense of the beleaguered organization, focusing on the health-care services the group provides for millions of women.

White House spokesman Eric Schultz said the administration strongly disagrees with the bill, adding, "We support them getting the types of services and health care they need."

Sen. Susan Collins, R-Maine, a long-time moderate, said she would oppose the proposal because it would immediately end the federal aid, "and I don't know how all the patients of Planned Parenthood could be absorbed" by other health care providers. She said such action should await an investigation into Planned Parenthood's practices.

Republicans want to block the money because of videos secretly recorded by an anti-abortion group showed Planned Parenthood officials describing their procedures for providing tissue from aborted fetuses for research.

Sen. Joni Ernst, R-Iowa, the bill's sponsor, said Planned Parenthood's role in obtaining fetal organs "is morally reprehensible and wrong." The bill would block federal funds for Planned Parenthood and transfer the money to community health centers and other providers.

Abortion foes say Planned Parenthood shouldn't provide the organs and have accused the group of profiting from it, which would be illegal. Planned Parenthood officials say they've done nothing wrong.

Republicans have 54 Senate seats but will need 60 votes to keep the bill alive.

The dispute spilled over onto the Democratic presidential campaign trail as well.

Front-runner Hillary Rodham Clinton told the New Hampshire Union Leader on Tuesday that the videos were "disturbing," but also said Planned Parenthood "for more than a century has done a lot of really good work for women." She said questions "about the whole process" should be addressed broadly, not aimed solely at Planned Parenthood.

Another Democratic presidential hopeful, Sen. Bernie Sanders of Vermont, said attacks on Planned Parenthood were "part of a long-term smear campaign by people who want to deny women in this country the right to control their own bodies."