Sen. Marco Rubio says he's a "no" vote on the GOP tax bill — at least in its current form.
Rubio says he wants the plan to expand the child tax credit so that it can help low-income families that pay payroll taxes but not regular income taxes.
If Senate Republicans lose two more votes, they'll be unable to pass the bill. Sen. Bob Corker voted no on the original Senate version of the bill and said his original concerns are still present.
Sen. Mike Lee has also been pushing for an expansion of the child tax credit, but a spokesperson for Lee told CNN he hasn't decided whether he'll vote for the final bill or not.
But Senate Majority Whip John Cornyn says the negotiators are pretty confident they'll win Rubio's vote back in the end.