(CNN) -- Mayors Against Illegal Guns, the group co-chaired by New York City Mayor Michael Bloomberg, released on Thursday the first television ad buy featuring family members of victims in the Newtown, Connecticut massacre.
In the spots--one is 60 seconds, the other is 90 seconds--family members talk about their loved ones and call on political leaders to embrace tougher gun laws. The ads come more than three months after a gunman killed 20 children and six adults at Sandy Hook Elementary School, in addition to his mother, before taking his own life.
The ads specifically emphasize a need for comprehensive background checks, a limit on high capacity magazines, and an assault weapons ban--proposals that have all been floated in Washington and in Connecticut's state legislature.
Many of the family members in the ads have been seen in Washington calling for stricter gun laws, including Neil Heslin, father of Jesse Lewis, and Chris and Lynn McDonnell, parents of Grace McDonnell. Jillian Soto, the sister of the late teacher Vicky Soto, and Terri and Gilles Rousseau, parents of another teacher Lauren Rousseau, also speak in the spots.
Focused on pending Connecticut legislation, the ads will run in the Hartford market. Their release comes the same day the group launches "The National Day to Demand Action," a major advocacy initiative that involves groups, such as Organizing for Action and former Rep. Gabby Giffords' group Americans for Responsible Solutions, for events across the country.
President Barack Obama will hold an event at the White House, where he will stand with mothers who are urging Congress to take action on measures to combat gun violence. He'll be joined by Vice President Joe Biden, law enforcement officials, victims of gun violence, and other stakeholders in the gun control debate.
"We cannot afford to wait for another tragedy -- it's long past time for elected officials to listen to their constituents and pass reforms like comprehensive background checks that we know will save lives," Bloomberg said in a release with the spot.
Group spokeswoman Erika Soto Lamb confirmed the commercial is separate from the $12 million ad buy by Mayors Against Illegal Guns, which was announced on Saturday. Those ads began airing in 13 states on Tuesday and are timed to put pressure on both Republican and Democratic senators home for the congressional Easter recess.
When lawmakers return the second week of April, the Senate will begin debate on a gun bill formally introduced by Senate Majority Leader Harry Reid last week. The legislation would expand the background check system, impose more school safety measures and introduce tougher laws on gun trafficking. Reid said he'll allow amendments to be added so the Senate can vote on other proposals, such as magazine capacity limits and a ban on semiautomatic rifles modeled after military-style assault weapons.
Recent polling, however, shows public support for gun restrictions has declined since the December shooting, as renewed attention has amplified on both sides of the debate. Shortly after the school massacre, 52% of Americans favored major restrictions on guns or making all guns illegal, according to a CNN/ORC International poll. That number has dwindled to 43%, according to the same poll conducted March 15-17.