Grover Norquist, president of Americans for Tax Reform, Brent Gardner, chief government affairs officer for Americans for Prosperity, and Adam Brandon, president of FreedomWorks, along with more than 70 leaders and individuals sent a letter to Congress urging them to not impose carbon taxes.

Other groups that signed the letter include the Goldwater Institute, the Competitive Enterprise Institute, the Independent Women’s Forum, and the Texas Public Policy Foundation.

“We oppose any carbon tax,” they wrote.

“A carbon tax raises the cost of heating your home in the winter and cooling your home in the summer. It raises the cost of filling your car. A carbon tax increases the cost of everything Americans buy and lowers Americans’ effective take home pay. A carbon tax increases the power, cost, and intrusiveness of the government in our lives.”

The letter was a reaction to mainstream Republican Sen. Mitt Romney saying he was considering co-sponsoring a carbon tax bill with Delaware Democrat Cris Coons.

Romney told E&E News the proposal would put a $15-per-metric-ton fee on carbon emissions.

“Taxes have never been my intent, but we’ll see what he has to say,” Romney said. “I would very much like to see us reduce our carbon emissions globally, and we’ll see if this might help.”

If Romney does co-sponsor the bill he would be the only Republican senator openly supporting it.

Last month, 75 leaders from multi-million dollar corporations like Microsoft, Nike, Pepsi and eBay, lobbied Congress to consider carbon pricing, according to Inside Climate News.

A 2017 Climate Leadership Council plan authored by former Bush and Reagan administration officials, called for a “conservative climate solution,” which proposed gradually increasing the carbon tax.