Conservative organizations poured money into a campaign to uphold an anti-union law in Missouri, as voters prepare to decide next week whether to reject a law designed to restrict the ability of private sector labor unions to bargain with employers for better wages and benefits.

Millions of dollars from anonymous donors have been spent in opposition to repealing the state’s “right-to-work” law. 

Campaign finance reports filed Monday show that political action committees (PACs) that oppose repealing the law raised a fraction of the cash of PACs that support repealing the law, according to records from the Missouri Ethics Commission. Missourians for Freedom to Work reported $848,300 in contributions and $1.19 million in expenditures during the last reporting period. The National Right to Work Committee, a nonprofit that promotes anti-union policies and has ties to the GOP mega-donor Koch brothers, contributed $533,000 to Missourians for Freedom to Work in the month of July.

The labor unions and progressive organizations leading the campaign to repeal the anti-union law have far outraised and outspent the corporate interests and conservative groups.

We Are Missouri, which opposes the “right to work” law, received more than $3.6 million in contributions during the last reporting period, and has raised more than $16.1 million in total contributions. The majority of contributions have come from labor unions in Missouri and across the United States.

Olivia Sandbothe, spokesperson for We Are Missouri, told Rewire.News the issue “touches a nerve,” and that people have been motivated by the opportunity to make a statement with the ballot measure. “This is a place where we can overturn one of these bad laws and do something that will actually benefit the people of this state for once,” Sandbothe said.

Freedom to Work and Missourians For Worker Freedom, PACs that support the anti-union law, received no contributions during the last reporting period.

Both PACs have been primarily funded by A New Missouri, a nonprofit associated with former GOP Gov. Eric Greitens. The dark money nonprofit, which has been the subject of alleged ethics violations and legislative investigations, has contributed $1.65 million to Freedom to Work and $350,000 to Missourians for Worker Freedom. A New Missouri has made no reported contributions since Greitens resigned as governor on May 29 amid multiple scandals.

Liberty Alliance, another PAC that opposes repealing the law, reported no contributions during the last reporting period.

Sandbothe said this campaign should serve as a reminder that laws pushed by out-of-state lobbying groups eventually have to answer to voters.

“Dark money can pour as much money as they want into this state, but in the end we do have the people’s veto,” Sandbothe said.