Republican senators say they are making progress on partially repealing and replacing Obamacare, but some lawmakers don't know which bill they will be voting on next week.

The confusion stems from uncertainty on which path GOP leadership will take on healthcare reform. GOP leaders have signaled they will hold a vote early next week to start debate on a House bill, passed in May, that would partially repeal Obamacare.

But it is not clear if leadership will then strip out the House bill and replace it with a 2015 bill that guts Obamacare but leaves it in place for two years while Republicans craft a replacement or another bill that would partially repeal Obamacare and immediately replace it.

Sen. John Thune, R-S.D., a member of leadership, provided some clarity when asked whether the Senate will vote on repeal and delay or the replacement bill, which is called the Better Care Reconciliation Act.

"I think probably straight repeal," he replied.

But GOP leadership doesn't have enough votes for either measure to pass.

Sen. Mike Rounds, R-S.D., said the Senate needed to advance the motion to proceed to debate and then move on to any legislation "that we have 50 votes for."

Vice President Mike Pence can break any 50-50 tie in the Senate, but with Sen. John McCain out after he was diagnosed with brain cancer, the GOP can afford to lose only one Republican vote.

Senate leaders huddled with members on Wednesday night to iron out differences with the repeal and replacement bill. While senators left the meeting saying they are making progress, some holdouts were uncertain of the next steps.

When asked by reporters Wednesday night if she would vote on the motion to proceed to debate on the legislation, Sen. Lisa Murkowski, R-Alaska, responded with a question of her own.

"We don't have a clear determination as to what it is we are voting for," she said.

Sen. Susan Collins, R-Maine is also confused about where the Senate goes next.

"I have no idea whether it is gonna be another version of the Senate bill or whether it is gonna be the 2015 repeal bill," she said Thursday.

Collins has opposed both the replacement bill and the repeal-only bill. Murkowski and Sen. Shelley Moore Capito, R-W.Va., joined her in not supporting repeal and delay, but the two senators are undecided on the replacement plan.

In addition to Collins, Sens. Rand Paul of Kentucky, Jerry Moran of Kansas and Mike Lee of Utah oppose the motion to proceed on the replacement plan. Lee and Moran were at the Wednesday meeting, but Collins and Paul did not attend.