SEATTLE (AP) — Microsoft Corp., REI and other businesses joined environmental and other groups Tuesday in testifying in support of Gov. Jay Inslee’s ambitious proposal to tax fossil fuel emissions to fight climate change.

Inslee has proposed a new tax of $20 per metric ton of carbon emissions that would start in 2019 and increase over time. Money raised pay for projects to reduce greenhouse gas emissions, manage stormwater and reduce wildfire risks. Some money would offset taxes to energy-intensive businesses and help low-income families.

“We believe the time has come for Washington state to accelerate its efforts to address climate change and we stand ready to work with you all to get that done,” Irene Plenefisch, Microsoft’s government affairs director, told state senators at a hearing in Olympia.

Inslee pitched his proposal as “an investment bill” when he testified before the senate energy, environment and technology committee.

If the Legislature doesn’t act on a carbon policy during the short 60-day session, a coalition of environmental, labor and other groups say they will move ahead with a citizen’s initiative this November.

With that prospect looming, some told lawmakers they would prefer to work through the legislative process.

“Without legislation, we know there are well-funded groups ready to pursue a ballot measure,” said John Rothlin with Spokane-based Avista Corp. “We’re among those that believe the best results will come from a collaborative effort here among people looking for fair and reasonable results.”

Avista, other utilities and industry groups had challenged the state over its clean air rule, which gradually limited greenhouse gas emissions from large industrial emitters. A Thurston County judge ruled in favor of those groups in December.

Rothlin and others said the $20 price per metric ton of carbon emissions was too high and they worried there was no cap on the price.

Previous plans to charge a fee for carbon pollution did not gain traction in the Legislature in previous sessions, including last year, and in 2016 voters rejected a ballot measure on a carbon tax.

Senate Republican Leader Mark Schoesler called it an “energy tax on working families.” “It’s still the concept that the voters rejected just a little over a year ago,” he said Tuesday.

Mo McBroom, director of government relations with The Nature Conservancy, said that “given the kind of support we saw today, the question is not so much whether we’re going to have strong climate legislation, it’s when and how.”

She added: “We have 55 days in front of us and lot of people leaning in to make sure the policy is as good as it can be.”

Stacey Smedley with Skanska Construction and co-chair of the Washington Business for Climate Action, said the measure aligns with the group’s four key priorities.

“This is the first time in the past three years we can actually come out and support a carbon tax bill,” she said.

But several critics said the measure would hurt consumers and businesses.

Bill Stauffacher, who spoke for the Northwest Pulp and Paper Association, said it would have a huge economic impact on that industry.

“Our initial analysis paints a stunning a painful picture about how we would be impacted,” he said.

The measure includes several exemptions, including aviation fuel and fossil fuels used in agriculture. Policy staff for Inslee said the impact on consumers from the tax would range from a 4 to 5 percent increase in electricity, a 9 to 11 percent increase in natural gas, and a 6 to 9 percent increase in gasoline.

Kim Powe, interim director of Puget Sound Sage, said she hoped to see provisions added that would make the bill more equitable, such as including a tax rebate for working families.

REI’s Marc Berejka told lawmakers that the bill is “a solid step forward.”

“It’s fantastic that this bill recognizes the importance of healthy forest and waters, that it combats forest fire and that sets aside money to address environmental hazards that disproportionately impact sectors that rely on a healthy environment,” he said.

Associated Press writer Rachel La Corte in Olympia, Washington, contributed to this report.