Days before President Obama and Mitt Romney take the stage at the University of Denver for their first debate, a survivor of the deadly shooting in nearby Aurora, Colo., is demanding the candidates deliver more precise plans on how they'd combat gun violence.

"I think it's fair to ask the men who want to lead the country to get past the platitudes and give us a serious plan to address a serious problem," Stephen Barton, 22, said. His statement was released today along with a new ad paid for by the United Against Illegal Guns Support Fund, a bipartisan gun control advocacy group.

Barton, from Southbury, Conn., was struck in the face and neck during a July 20 mass shooting that killed 12 people and left 58 wounded.

The TV spot, which begins airing today, is meant to put pressure on the two candidates who, while expressing sympathy for the victims, have been hesitant to suggest new legislation might be necessary to prevent future attacks.

Barton calls himself "lucky" for having survived his grievous wounds.

"In the next four years, 48,000 Americans won't be so lucky, because they'll be murdered with guns in the next president's term. Enough to fill over 200 theaters. So when you watch the presidential debates, ask yourself: Who has a plan to stop gun violence? Let's demand a plan."

Romney, who during his time as governor of Massachusetts signed a "permanent" assault weapons ban, has since adapted a softer stance, calling "existing laws" sufficient.

"I still believe that the Second Amendment is the right course to preserve and defend and don't believe that new laws are going to make a difference in this type of tragedy," he told CNBC's Lawrence Kudlow three days after the massacre.

President Obama has offered little more, suggesting "common sense" measures to ban the mentally unstable from buying deadly weapons. Like Romney, he has distanced himself from past support of stricter legislation, including a 1996 mailer in which he backed a ban on "the manufacture, sale and possession of handguns."

"The moment of silence from our national leaders has lasted too long, " Boston Mayor Thomas Menino, a co-chair of Mayors Against Illegal Guns, said in a press release accompanying the ad. "It's time for real action to prevent the 34 murders that happen every day because of gun violence."

Barton, a recent Syracuse graduate who was passing through Aurora during a cross-country bike trip, will continue to work with the mayoral group before returning to his studies as a Fulbright scholar.