Another Senate Republican has spoken out against Majority Leader Mitch McConnell’s plan to repeal ObamaCare without a replacement, dampening GOP efforts to move forward.

Sen. Rob Portman, R-Ohio, told reporters in a conference call Tuesday that the strategy was not “appropriate,” but neglected to say whether he would vote against taking up the House health care bill, the Hill reported.

“I have said consistently that I support repeal and replace, and I’m not giving up on doing both of those things,” Portman said. “I don’t think it’s appropriate just to repeal, we’ve also got to put a replacement in place.”

Portman is the fourth Republican to push back on the plan by McConnell, R-Ky. Previously, West Virginia Sen. Shelley Moore Capito, Alaska Sen. Lisa Murkowski and Maine Sen. Susan Collins signaled they also oppose legislation that would repeal ObamaCare without offering a replacement.

"As I stated earlier this year, I cannot vote to proceed to repeal the ACA [Affordable Care Act] without reform that allows people the choice they want, the affordability they need and the quality of care they deserve,” Murkowski said.

McConnell said Tuesday that the Senate will hold a procedural vote to repeal ObamaCare “early next week,” but with four Republicans already announcing their opposition, debate on a bill doesn’t seem likely.

Republicans have 52 seats in the Senate. McConnell can afford to lose only two Republican votes, with Vice President Mike Pence as a tiebreaker, if all Democrats vote against the effort.

Fox News’ Chad Pergram contributed to this report.