A Republican-backed group pushing for Congress to pass a carbon tax has raised more than $5 million this year after adding new corporate funders Thursday, including America’s two largest automakers: GM and Ford.

The carmakers, along with technology company IBM, are giving $100,000 each to Americans for Carbon Dividends, the lobbying arm of the Climate Leadership Council, a group led by former Republican Secretaries of State James Baker III and George Shultz.

Texas-based power companies Vistra Energy and Calpine Corp. are also providing funding to the group, with Vistra committing $1 million over two years.

“What you are seeing is a consensus position from all sectors of corporate America saying we need a national carbon price,” Climate Leadership Council CEO Ted Halstead told the Washington Examiner. “It's not just energy majors and utility majors."

Oil and gas giants BP, Shell, ConocoPhillips, and Exxon Mobil have already donated money to the group, which advocates returning carbon tax revenue to taxpayers.

“Ford supports policies that take an economic and sectorwide approach to reducing carbon emissions in a cost-effective way," Rachel McCleery, a Ford representative, told the Washington Examiner. “We believe the Climate Leadership Council’s position meets those goals at a time when there is a growing desire among lawmakers to find consensus on climate-change legislation.”

Jeannine Ginivan, a GM representative, noted the company was already a founding member of the Climate Leadership Council and is amplifying its support of the carbon tax and dividend plan by donating money.

“We recognize that the transportation sector needs to be a part of the solution [to climate change], which is why we believe in an all-electric future,” Ginivan told the Washington Examiner.

Halstead said the $5 million that Americans for Carbon Dividends raised in 2019 will allow the group to ramp up its lobbying in 2020. The group’s managing director, former Republican Rep. Ryan Costello, has been banned from lobbying because he recently left Congress but can begin lobbying in January.

The group also expects to invest in more paid media, state fieldwork, grassroots organizing, and additional staff and consulting.

Americans for Carbon Dividends launched a six-figure advertising campaign in November.

Halstead said he hopes Congress introduces bipartisan legislation in both chambers mirroring the group’s proposal next year.

The Climate Leadership Council’s plan would impose a gradually rising carbon tax beginning at $40 per ton, increasing 5% every year, and return the money to taxpayers as quarterly payments of equal size for all households to offset higher energy prices.

This would cut U.S. carbon emissions in half by 2035, the group said, a greater amount than what the Obama administration pledged to do under the Paris climate accord.

In a bid to win more support, the group recently stripped from its plan a controversial provision that would have protected oil and gas companies from certain lawsuits based on their historical emissions.

The proposal, however, retains a second component of what backers call a “grand bargain” to win over the industry, namely, keeping a plan to scrap or prevent carbon regulations of power plants and all other stationary sources imposed by the Environmental Protection Agency, which would be redundant with the tax.

Businesses and economists contend a carbon tax is the simplest and most efficient way to address greenhouse gas emissions, applying a per-ton fee for large emitters, such as power plants and refineries, and encouraging energy producers to switch to cleaner alternatives.

Conservatives say it is a tax hike that would disadvantage the U.S. economy relative to other high-emitting countries.

Most Republicans oppose carbon pricing. The exceptions are two House Republicans, Rep. Francis Rooney of Florida, who is retiring, and Rep. Brian Fitzpatrick of Pennsylvania.

Halstead said he hopes the backing of wide swaths of corporate America for a carbon tax and dividend will encourage Republicans to reconsider.

“Little by little, key Republican validators and stakeholders are lining up behind our carbon tax and dividend plan, and that makes it much safer for Republican members to lead,” he said.