Abortion remains a make-or-break issue for Sen. Ben Nelson in health care reform talks, a spokesman said today, responding to an abortion rights leader's remark that the Nebraska Democrat might be open to a cloture vote on a bill that didn't contain such language.

Nelson is poised to present language in the Senate similar to the abortion funding restrictions authored by Michigan Democrat Bart Stupak in the House, and he won't vote for cloture without anti-abortion provisions, spokesman Jake Thompson said.

However, Nancy Northup, president of the Center for Reproductive Rights, said that a meeting with a Nelson staffer left her with the impression that while Nelson wouldn't support a bill without strong anti-abortion language in it, he would be open to a cloture vote "We are hopeful that the senator will remain open in that regard," Northup said in an interview with NationalJournal.com.

One of Nelson's anti-abortion colleagues is showing some flexibility on the cloture vote. Sen. Robert Casey, D-Pa., told CongressDaily that the lack of an abortion provision may not prevent him from moving the bill along to a final vote. Majority Leader Harry Reid, D-Nev., will need both Casey and Nelson to reach the 60-vote threshold to push the bill to a final vote.

Theresa Poulson contributed to this report.