A BALLOT QUESTION that would classify Uber and Lyft workers as independent contractors while granting them certain workplace benefits is shaping up to be the biggest and most expensive fight on the ballot this November, according to newly filed campaign finance reports, while a campaign to raise the income tax rate on income over $1 million is also turning into a multi-million-dollar battle.

Fundraising reports covering 2021 were due to the Office of Campaign and Political Finance Thursday. A glance through those reports shows who the earliest supporters are of the three ballot questions and one constitutional amendment heading toward the November ballot.

The committee supporting the ride-hailing driver question, Flexibility and Benefits for Massachusetts Drivers, raised a staggering $17 million last year. Ride-hailing company Lyft contributed nearly $14.4 million. The Boston Globe reported that a single $13 million contribution Lyft made on December 30 is the largest donation ever listed on the Office of Campaign and Political Finance’s website. Among other companies that rely on similar business models, Uber gave $1 million, while Doordash and Instacart each gave around $1.2 million.

Uber and Lyft won a similar ballot fight in California, after a campaign that was the most expensive in California history. The law remains tied up in court after a judge ruled it was unconstitutional.

The Coalition to Protect Workers Rights, a labor-funded group formed to oppose the ballot question, has raised just over $1 million. Massachusetts unions representing health care workers, aerospace workers, teachers, government workers, painters, laborers, and others contributed the bulk of that money. The George Soros-funded Open Society Foundations gave $100,000. The business and technology-backed Omidyar Network of California, which was founded by eBay founder Pierre Omidyar and describes itself as investing in inclusive and equitable societies, gave $150,000.

The other big fight heading toward the ballot is over a constitutional amendment that would raise the tax rate by 4 percentage points on income over $1 million.

When the amendment was initially going to be voted on in 2018 – before the Supreme Judicial Court ruled it illegal – Raise Up Massachusetts, a coalition of labor, clergy, and liberal organizing groups, raised $2.7 million. This time, the question was submitted through a different process that avoids the same legal issues.

So far, Raise Up Massachusetts has raised $1.2 million for this year’s campaign. Some of its larger donors include the Jewish Alliance for Law and Social Action, the health care workers union 1199 SEIU, the Massachusetts Teachers Association, SEIU Local 509, National Association of Government Employees, and several other unions. The Omidyar Network – the same organization opposing the gig worker ballot question – gave $100,000.

Another ballot committee campaigning for the surtax, the Coalition for Social Justice, raised $16,800, of which $15,000 came from Marlene Pollock of New Bedford, a retired Bristol Community College professor who founded the coalition.

A ballot committee formed to oppose the income surtax, the Coalition for a Strong Massachusetts Economy, raised $437,000 in 2021, mostly from large donations by business executives. They include: Robert Reynolds, CEO of Putnam Investments ($200,000); Nino Micozzi, owner of the real estate company Micozzi Management ($100,000); Jeffrey Markley, CEO of the Markley Group, which runs data centers ($50,000); and Mark Casady, founder of the investment firm Vestigo Ventures ($25,000).

Other business-backed or conservative-leaning organizations – the Massachusetts Fiscal Alliance, the Pioneer Institute, the National Federation of Independent Businesses, and the Massachusetts High Technology Institute – have been lobbying lawmakers, publishing research, and holding events opposing the policy. Paul Craney, a spokesperson for the Massachusetts Fiscal Alliance, said organizations like his have for years been educating the public on the policy, but not spending money specifically to defeat the ballot question, which is why his group has not filed as a ballot committee.

Two other questions heading toward the November ballot are each funded by a single source.

The Massachusetts Package Stores Association is the sole funder behind a ballot question that would increase the number of beer and wine licenses one entity can hold from nine to 18, while reducing the number of hard liquor permits. As CommonWealth reported, the question is being billed as a compromise alternative to a proposal made by Cumberland Farms in 2019 that sought to eliminate the license cap. The Massachusetts Package Stores Association put $404,000 into the effort last year, almost all to pay an agency to collect signatures.

Another ballot question seeks to lower dental costs by limiting how much money dental insurers can spend on administrative costs. The Committee on Dental Insurance Quality is funded entirely by orthodontist Mouhab Rizkallah, who gave $501,000. Attorney General Maura Healey has accused Rizkallah of fraud related to claims he submitted to MassHealth.

There do not yet appear to be ballot committees formed to oppose either of these questions.