Sen. Marco Rubio (R-FL) will oppose the Republican Tax Cuts and Jobs Act unless it includes an expansion of the child tax credit.

According to the Washington Post, a Senate GOP source revealed that Rubio will oppose the Republican Tax Cuts and Jobs Act. Sens. Mike Lee (R-UT) and Rubio proposed an expansion of the child tax credit. Lee has yet to say whether he will oppose the tax bill in its current form.

If Rubio opposes the tax legislation, Republicans can only afford to lose one more vote in the Senate and have Vice President Mike Pence pass the bill through Congress’s upper chamber. Sen. Bob Corker (R-TN) revealed that he would oppose the Republican tax bill because of its supposed effects on the federal deficit.

House and Senate Republicans announced this week that they have struck a deal on the final details of the tax legislation. Republicans hope to unveil the final form of the Tax Cuts and Jobs Act this week and have the bill pass through both chambers of Congress next week.

The deal sets the top individual tax rate at 37 percent, down from the current rate of 39.6 percent and lower than the Senate bill’s proposed rate. The compromise legislation would set the corporate rate at 21 percent, higher than the House’s proposed 20 percent.

Conservatives and business leaders ideally hoped to lower the corporate rate to 20 percent.

Rubio reacted to the news that the final tax bill will decrease the top individual rate.

Rubio asked, “If you make $40,000, we can’t find the money to increase the child tax credit, but if you make a million a year we can?”

President Donald Trump said that passing the tax reform bill would ensure a “Merry Christmas” for the country.

Trump declared that passing tax reform can “be the beginning of the next great chapter for the American worker.”