Seattle ? Leaders of this famously green city last year passed the nation’s first grocery bag fee, and other cities around the nation quickly followed.

But the plastics industry has been fighting back, bringing lawsuits, aggressively lobbying lawmakers and bankrolling a referendum in Seattle to overturn the 20-cent charge. The measure goes before voters Tuesday, and polls show marginal support after the industry spent $1.4 million, outspending supporters about 15-to-1.

If the bag fee fails in an eco-conscious city like Seattle, observers say, it will be a tough sell elsewhere.

“This amount of money is about bullying public officials,” said Rob Gala, a spokesman for Seattle Green Bag campaign, which has raised about $93,000 to back the fee.

In California, bag manufacturers successfully sued Oakland and Manhattan Beach after those cities banned plastic bags. The bag makers complained that officials didn’t prepare a report detailing the environmental impact, such as the increased use of paper sacks.

Seattle’s fee is unusual in that it also covers paper bags, which the city determined are worse for the environment than plastic. Targeting only plastic bags, the city said, would push people to use paper, resulting in greater greenhouse gases.

Plastic bag supporters say paper bags are more costly, take more energy and water to make, and release methane — a greenhouse gas — when they decompose. But plastic bags are recycled at a lower rate than paper sacks, according to the Environmental Protection Agency, and they take hundreds of years to break down in landfills.