The book, which is being co-written by her husband, is slated to be released in June and titled Enough: Our Fight to Keep America Safe from Gun Violence.
Her op-ed titled “A Senate in the Gun Lobby’s Grip” blasted senators for not approving the measure after a string of shootings, including the one in Newtown, Conn., which left 20 children dead in 2012.
She branded the senators who voted against the bill as cowards and urged activists and constituents to stop donating and voting for those senators.
“These senators made their decision based on political fear and on cold calculations about the money of special interests like the National Rifle Association,” she wrote at the time.
Since the shooting, Giffords has been a fierce advocate for gun control. Her super-PAC, Americans for Responsible Solutions, reported raising $12.5 million in 2013.
It will be her second book since being shot in the head at an event in Tucson, Ariz., in 2011.
Her first book detailed her recovery after the shooting. Giffords recently released a video showing her driving for the first time since the incident.