Sen. Bob Corker said Tuesday a "backstop" to curb future budget deficits could help to win his crucial vote for the GOP tax bill.
The Tennessee Republican and others are seeking the protection in case the nearly $1.5 trillion in proposed tax cuts do not meet the GOP's expectations for sparking economic growth. The "trigger" described by Corker would raise taxes if the plan does not boost the U.S. economy enough.
"What several of us have asked for is a backstop or trigger in that event we don't meet the projections that have been laid out — since we're not going to score it — that we have a backstop. And so that's what we've been working on throughout the weekend and feverishly today," Corker told CNBC's "Squawk Box."
"So, I hope we'll get there. I know it's important not just to me, but numbers of members who want to make sure that, for some reason these projections are off, we don't have the growth that's been laid out, it doesn't generate revenues, that we're not passing off increased debt to future generations," he added.
Asked who would bear the brunt of the tax increases under the backstop provision, the senator said he did not want to take away from the "certainty" of tax policy that businesses would want to see to invest. Prompted on whether that means individuals would see their taxes raised while corporations would not, Corker responded that "both" would have an increase.
The Senate bill as it stands only temporarily cuts individual taxes while permanently chops corporate rates, in order to comply with Senate budget rules.
Corker, who has expressed fears about expanding U.S. budget deficits by trimming taxes without new revenue, is one of several Republican senators who have not yet committed to supporting the GOP bill. Republicans, who hold 52 Senate seats, can only lose two votes and still pass the bill under special budget rules, assuming all Democrats and independents vote against it.
Sens. Ron Johnson, R-Wis., and Steve Daines, R-Mont., have said they oppose the current bill due to its treatment of so-called pass-through businesses. Those businesses, which are taxed at individual rates, get fewer benefits under the plan than corporations, the senators say.
Other senators, including Jeff Flake, R-Ariz., and James Lankford, R-Okla., have also expressed doubts about the deficit.
On Monday, Corker suggested he could oppose the Republican tax bill in a procedural Senate Budget Committee vote Tuesday.
"Very possible. Yeah. Sure," the Tennessee Republican responded Monday when asked if he could vote against the proposal.
On Tuesday, he said he believes a plan can meet his goals and Johnson's simultaneously. It is unclear how the Senate could cut the burden on pass-throughs further while keeping budget deficits in line.
Corker also showed little enthusiasm about the individual side of the Senate tax bill.
"If we could take the entire individual side of this, throw it in the trash can, and take it directly to the incinerator, I would be thrilled if we were only dealing with the business side as it's turned out," he said.
Corker added that he is "willing to swallow" the tax policy for individuals if Republicans can reduce the burden on businesses without increasing deficits.
The senator, who recently spoke out against President Donald Trump, also told CNBC it is "ridiculous" that anyone could claim he would vote against something "that's good policy because of some rift that's occurring."
The lowest-income Americans would take the biggest hit under the tax bill, according to the nonpartisan Congressional Budget Office.