On the one-month anniversary of the shootings in Newtown, Conn., Mayors Against Illegal Guns, the gun-control advocacy group led by Boston Mayor Thomas Menino and New York Mayor Michael Bloomberg, released a television ad intended to sway political leaders to enact gun control measures.

"Today we remember the lives that were needlessly lost one month ago, and the 33 lives taken by gun violence across our country every day,” Menino said in a statement. “But we also continue our call for action to take the illegal guns out of our neighborhoods, and tragedies like Newtown out of our nation's future. This time must be different. Our leaders in Washington must act, and pass the common-sense gun reforms necessary to protect our children and communities."

The ad features relatives of shooting victims demanding political action on the issue.

Bloomberg also released a report describing gun industry’s efforts to lobby against funding for research on gun violence.

Since the Newtown shooting, the group said it has added more than 100 mayors to its rolls, and grown to “more than one million” supporters.