The National Federation of Independent Businesses will spend about $1 million attacking two U.S. Senate challengers, one of them being U.S. Rep. Tom Allen (D-Portland) who is challenging Sen. Susan Collins (R-Bangor).

The Hill reports that the NFIB is doing this in their opposition to the Employee Free Choice Act, legislation that seeks to make it easier to unionize.

The bill’s proponents, including Allen, say that the bill will help labor groups and the middle class. Opponents, such as Collins, say they oppose the bill because it contains a means to circumvent the secret ballot that usually occurs in the union organization process.

Reporter Aaron Blake describes the ad: “The ads are slickly produced and feature an employee working his way through a building as he is surveilled in various ways by higher-ups.”

U.S. Sen. Susan Collins picked up the endorsement of NFIB this week. NFIB vice president Lisa Goeas said in a release: “Sen. Collins has been a good friend of small business since she arrived in Washington. She has provided key leadership on important issues such as access to affordable healthcare, and we look forward to continuing to work with her in the next Congress.”