SEATTLE (AP) — Washington Gov. Jay Inslee is backing a new proposed ballot initiative that would charge a fee on carbon pollution.

Inslee said he supported it when asked Tuesday at the Center for American Progress conference in Washington D.C.

Inslee spokeswoman Tara Lee said he believes it's a continuation of work in the state to fight climate change.

A broad coalition of tribes, environmental, labor and other groups are gathering signatures to qualify Initiative 1631 for the November ballot.

The proposal would charge $15 per metric ton of carbon emissions starting in 2020 and later increase $2 each year until the state meets its carbon emissions reduction goal.

Sponsors say it will hold polluters accountable while investing in clean energy and protecting the environment. Critics warn it will raise prices on consumers.

Inslee didn't support the carbon tax measure that voters rejected in 2016. He also proposed but failed to get support for a carbon tax bill in the most recent legislative session.