I-976 is the latest brainchild of Tim Eyman, the prolific initiative promoter. According to a state fiscal analysis, passage of the measure would cause government agencies throughout Washington state to lose about $4 billion in funding for transportation projects over the next six years.

Eyman, meanwhile, says approval of the ballot measure would force agencies to reprioritize their spending, while removing taxes he characterizes as deceptive and unfair.

The initiative would reduce car-registration fees that are paying for new light rail projects in the Puget Sound region, while eliminating local fees that pay for bus service, road maintenance and other transportation needs in cities throughout the state.

Those are tax cuts that Amazon and other businesses would like to prevent.

To date, Amazon has donated $400,000 to the committee working to defeat I-976, according to state campaign finance records. An Amazon spokesperson said the company was also donating $100,000 more, which has yet to appear in state records.

That $500,000 in donations makes Amazon the second largest contributor to the opposition campaign, a political-action committee that calls itself Keep Washington Rolling. The top donor to the opposition committee is Microsoft, which has contributed $650,000.

“We oppose I-976 because its passage would force essential transportation projects and programs to be delayed or abandoned at a time when the growth of our economy and our population demands more investment in transportation infrastructure, rather than less,” wrote Irene Plenefisch, government affairs director at Microsoft, in an emailed statement.

“The results would be more congestion, more greenhouse gas emissions, fewer economic opportunities, and a lower quality of life for everyone here,” Plenefisch wrote. “It would be a dangerous and unfortunate step backward.”

Representatives from Amazon and Microsoft did not make themselves available for an interview.

All told, the business community has spent about $2.9 million on the campaign to defeat I-976. That sum accounts for nearly two-thirds of the total contributions to the Keep Washington Rolling campaign.

Some of the other businesses spending heavily to fight I-976 include Vulcan, the late Paul Allen’s investment company, which donated $200,000 to the opposition campaign; Expedia, which donated $100,000; and Alaska Airlines, which donated $65,000.

Unlike in some of this year’s hotly contested Seattle City Council races, though, businesses and labor unions aren’t on opposing sides of I-976. Labor groups account for about 14% of the total funds donated to the Keep Washington Rolling campaign, joining businesses in opposing the initiative.

Heather Weiner, a Democratic political consultant, said that’s because of one simple factor: “jobs.”

“This is about infrastructure jobs and transit jobs — it’s very much about good-paying jobs,” said Weiner, currently working for the Civic Alliance for a Progressive Economy (CAPE), a political action committee heavily backed by labor unions.

CAPE was designed to counterbalance the similarly named Civic Alliance for a Sound Economy (CASE), which is sponsored by the Seattle Metropolitan Chamber of Commerce. Amazon recently donated $1.45 million to CASE, which is working to elect more business-friendly candidates to the city council.

Amazon and the chamber fought hard last year against a per-employee “head tax” on big businesses, which the Seattle City Council passed to raise money for homeless services. Facing a possible referendum effort and negative polling, the council ended up repealing the head tax about a month after passing it.

Weiner said car tabs don't directly affect Amazon in the same way the head tax would have. That makes it easier for the company and other businesses to oppose I-976 and its promised tax cuts, she said.

She said in this case, what's in the best interest of the general public happens to be the same as what is in the best interest of big corporations, but that's not always true.

“It is very much appreciated when these big businesses provide financial support for good ballot initiatives, like defeating I-976, affirmative action, trans rights and gay marriage,” Weiner said. “It’s important to note those initiatives do not affect their bottom line, and may in fact help their bottom line.

“In the case of I-976, voters are voting on how to tax themselves,” Weiner said.

Alicia Teel, a spokesperson for the Seattle Metropolitan Chamber of Commerce, noted that the group’s members have supported other tax measures before, such as the Move Seattle transportation levy and last year’s citywide education levy.

“The key for the chamber and the business community is, ‘Is there a plan for how this money is going to be used?’ ” said Teel, referencing the chamber’s key criticism of the Seattle head tax.

The chamber and Amazon were also big supporters of Sound Transit 3, the $54-billion ballot measure that Puget Sound voters approved in 2016 to pay for light rail projects and increased bus service, Teel said. As approved, the package promises to extend light rail to Ballard and West Seattle, as well as to Tacoma and Everett, by 2041.

“We have a long history of supporting transit and transportation funding,” wrote Aaron Toso, a spokesperson for Amazon, in an email Thursday.

Yet Sound Transit 3 is one of the main targets of I-976. Sound Transit officials say if I-976 passes, it will cost the agency about $20 billion through 2041, forcing them to curtail or delay some of the voter-approved light rail projects.

Eyman, the initiative’s sponsor, says that’s not something that worries him. He is critical of how Sound Transit went about calculating car tab fees to pay for the light rail package, which the agency said at the time would increase annual vehicle registration fees by $80 for a vehicle valued at $10,000.

But the agency is using a vehicle valuation schedule from the 1990s that overestimates the value of cars in their first 10 years of life, which led many people to object to what they thought were higher-than-expected car tab fees. The fees apply in Sound Transit's three-county taxing district: King, Pierce and Snohomish counties.

“The pigs at the trough that are feeding off the dishonest vehicle tax are fighting hard to make sure the dishonest revenue keeps rolling in,” said Eyman, who is being sued over accusations he enriched himself with donations meant to support previous initiative campaigns. “They want to keep the gravy train rolling.” He directed his comments, provided in a phone call Thursday, not just at Sound Transit and government agencies, but also at the labor groups and businesses working hard to defeat I-976.

In addition to cutting annual vehicle registration fees to $30, I-976 would require future car-tab fees to be calculated based on a vehicle’s Kelley Blue Book value, rather than a depreciation schedule approved by the state Legislature.

Opponents of the measure have emphasized in their advertisements that I-976 would affect more than just Sound Transit. It also would cut funding raised by Transportation Benefit Districts in about 60 cities, including Seattle, meaning less money for road maintenance and local buses, the Keep Washington Moving campaign says.

Eyman has raised substantially less money to support his $30-car-tab effort than businesses and other groups have raised to fight it. Committees supporting the initiative have raised about $225,000 in contributions. In addition, Eyman has loaned $500,000 of his own money to the effort to pass I-976, campaign finance records show, meaning the campaign owes more money than it has raised.