The Senate's tax overhaul bill is a "huge tax increase" on certain businesses, said Robert Murray, chairman and CEO of coal giant Murray Energy.
Murray, who has been a big supporter of President Donald Trump, told CNBC he's specifically upset about the decisions to keep the alternative minimum tax and to take away the deduction for net interest expense as a cost of business.
He said the Senate legislation will raise Murray Energy's taxes by $60 million a year, "notwithstanding the other so-called benefits the Senate has proposed."
"This means that very capital-intensive, highly leveraged employers, like coal-mining companies, will be forced out of business, with tragic consequences for our families and for many regions of our country," Murray said in an interview with "Closing Bell" on Monday.
The Senate had planned to eliminate the AMT, as the House bill did, but last-minute changes kept the provision in the legislation. The House and the Senate now must reconcile their bills before sending a final version to Trump to sign into law.
Murray, who heads up one of the nation's largest coal-mining companies, is known for his dire warnings about the decline of coal.
In February, he said global warming is a hoax and repeated a debunked claim that the phenomenon cannot exist because the Earth's surface is cooling.
When asked what the effective tax rate of Murray Energy is, Murray replied, "We don't pay a tax rate right now because we have a lot of net loss carry-forwards. We have a lot of debt."
However, he said, whether the company has a tax rate is not the issue.
— CNBC's Tom DiChristopher contributed to this report.