The political arms of the League of Conservation Voters and the United Steelworkers are teaming up on a $3.1 million investment in four Senate races. 

The two groups will invest in voter persuasion and turnout field programs in Arizona, Montana, Nevada and Ohio. Digital, television and direct mail spending will also be part of their efforts. 

Through canvassing and direct mail, for example, the groups plan to target 106,000 voters in the Phoenix metro area to help elect Rep. Kyrsten Sinema in Arizona. A similar number of voters will be targeted in the Henderson and Las Vegas metro areas to help elect Rep. Jacky Rosen to the in Nevada, while about 59,000 voters will be targeted in Cincinnati and Hamilton County to help re-elect Ohio Sen. Sherrod Brown. In Montana, the two groups are investing in a vote-by-mail signup program statewide with canvassing in Missoula and Bozeman to help re-elect Sen. Jon Tester.

The joint spending will come through New American Jobs Fund, a super PAC through which the LCV Victory Fund and USW Works first partnered on voter mobilization in 2016.

“We don’t have to choose between good jobs and clean air and water, and that’s why conservationists and labor are coming together once again to elect senators who share those values,” LCV President Gene Karpinksi said in a statement Monday. 

“Control of the U.S. Senate is in play, and this effort will directly communicate with the tens of thousands of voters who will decide the outcome of the election in these key states,” United Steelworkers International President Leo W. Gerard added.