(CNN) - New York City Mayor Michael Bloomberg is putting his money where his mouth is when it comes to politics and gun legislation.
His super PAC, Independence USA, is dropping more than $1 million in advertisement money against a Democratic candidate running in a special election to replace former Rep. Jesse Jackson Jr. of Chicago.
The candidate, former U.S. Rep. Debbie Halvorson, has an "A" rating from the National Rifle Association and opposes proposals that call for a renewed ban on assault weapons similar to the one that expired in 2004.
Halvorson, who says she doesn't own a gun, points to the assault weapons ban that's been in place for two decades in Cook County. But, she adds, the city of Chicago still "has the highest murder rate in the country."
"For whatever reason, I'm the only candidate who's willing to be honest and just not cave on the issue," she said.
Asked if she's worried about the amount of money spent in attack ads against her, she said, "How could you not be concerned about more than a million coming from one billionaire in New York?"
"If he thinks he can buy a congressional race in Illinois, he's never going to stop," she continued.
A leading contender in the race to represent Illinois’ 2nd Congressional District, Halvorson stresses a stronger focus on revitalizing mental health services, enforcing current gun laws and implementing universal background checks.
"If we continue the cycle of passing one ban after another and yet ignore the real issues that impact crime, it would not be the most effective use of our resources," she says.
The new television ad targeting the former congresswoman says that gun violence is "out of control" and "Debbie Halvorson will make it worse."
"Debbie Halvorson's record: more guns in the hands of criminals," the narrator states. The commercial hits airwaves a little more than two weeks before the Democratic primary.
The former congresswoman, however, argued the ad was "shameful" and a "complete lie."
Stefan Friedman, spokesman for Independence USA PAC, said that "as Congress considers President Obama's package of gun safety measures, it is clear that NRA support and opposition to these reasonable reforms is an electoral liability."
Officials with the group say it has reported $400,000 in spending in each of the last two weeks on the race. With another weeklong buy for the new spot, that should put the total amount spent on $1 million against Halvorson.
Bloomberg, a leading voice in the gun control debate, started his super PAC last year with an agenda to support candidates that agree with him on major issues, including gun laws. By the end of 2012, the group spent nearly $10 million.
The mayor co-chairs "Mayors Against Illegal Guns," a group with a big presence in the recent back-and-forth over tougher gun laws. The organization has also taken out television ads, though on a more national scale.
The ad against Halvorson comes just days before the president is scheduled to travel to his adopted home town Chicago on Friday, where he's expected to address the city's gun violence. More than 500 people were killed in gun-related deaths last year, according to authorities. The first lady attended a Chicago funeral Saturday for a teenager killed by gunfire last month.