Sandy Hook families to ride AF-1 to DC, lobby Senate

WASHINGTON (CNN) -- Eleven family members of children killed at Sandy Hook elementary school will fly to Washington with President Barack Obama on board Air Force One Monday, according to a senior administration official and representatives of the families.

They'll spend two days lobbying senators to pass gun safety legislation, after joining the president for an event in Hartford, Connecticut at which the president will press Congress to act in the wake of the Newtown killings.

The group, members of Sandy Hook Promise, will arrive in Washington with a letter signed by 120 extended family members of Sandy Hook victims. They will encourage both Democratic and Republican senators to support background checks for all gun purchases, a limit on high-capacity ammunition and stronger gun trafficking provisions, among other steps, while members of Congress continue to debate new gun control measures. The group is not taking a position on the assault weapons ban, legislation that already lacks enough support to pass through Congress.

Sandy Hook Promise was established days after the attack in Newtown to support the victims of the tragedy and advocate for gun safety laws, according to the group's spokesperson Lara Bergthold.

A Sandy Hook mother, Nicole Hockley, will introduce the president before his remarks Monday. Hockley's six-year-old son, Dylan, was killed in the December shooting and the stay-at-home mom has been working full-time since then advocating for new anti-violence laws.

President Obama will speak the University of Hartford Monday evening, after meeting with victims' families. Sources say he will talk about the gun safety laws the state of Connecticut recently passed and highlight the Newtown families' role in lobbying for their enactment.

Monday's event, which is expected to be emotional, is the latest event by the president to push Congress to pass legislation to address gun violence. Vice President Joe Biden, Attorney General Eric Holder and first lady Michelle Obama are also expected to hold events on the same topic this week.