(THE HILL) — Time is ticking away on Senate Majority Leader Mitch McConnell’s hopes of passing ObamaCare repeal legislation before the July 4 recess.

A CBO score that found the legislation would leave 22 million more people without insurance in the next decade has raised the stakes on a procedural vote that could come as soon as Tuesday.

At least four Republicans say they may vote against their party on the motion to proceed, underscoring the opposition to McConnell’s bill.

The defectors include centrist Sen. Susan Collins (Maine), who panned the bill on Twitter Monday evening; fellow moderate Sen. Dean Heller (R-Nev.); and two conservatives, Sens. Rand Paul (R-Ky.) and Ron Johnson (R-Wis.).

McConnell can only afford two defections.

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