The League of Conservation Voters is launching a $3 million ad buy in North Carolina that attacks Republican Sen. Richard M. Burr‘s environmental record. 

The ad says Burr took hundreds of thousands of dollars from oil and energy companies but gave them “billions in tax breaks” and voted “against clean energy jobs.” 

Service Employees International Union and the American Federation of State, County and Municipal Employees spent $1.8 million on an ad campaign with a similar message, The News & Observer reported. 

A spokeswoman for Burr countered that “outside groups never dictate his votes or positions.”

The Rothenberg & Gonzales Political Report/Roll Call rates the race Tilts Republican.