The gloves are off in the race for the 12th Congressional District.

The campaign of Democratic candidate Bill Enyart, a Belleville attorney, on Wednesday released audio of a radio commercial that the campaign said is being unleashed.

Jason Bresler, Enyart's spokesman, said the ad has not yet aired but it will air on radio stations throughout the 12th District.

The Enyart commercial criticizes Republican opponent Jason Plummer's decision not to release his tax returns.

The spot opens with ominous-sounding music, and a narrator asking, "What's Jason Plummer hiding? He's running for Congress, but he refuses to make any of his tax returns public."

Plummer's campaign issued a statement in response: "Mr. Enyart continues to be more interested in Jason's income than the lack of income of thousands of families through the district due to the failed policies of President Obama and (former Democratic House speaker) Nancy Pelosi."

The narrator in the ad also says Plummer "needs to be honest about how much he avoids in taxes," and says he could "pocket around $300,000 in cash" through tax breaks for the wealthy.

The spot uses the word "millionaire" three times and the word "billionaire" once. It accuses Republicans of "extending tax cuts to millionaires like Jason Plummer."

Plummer works for his family's lumberyard chain.