The Atlanta-based Centers for Disease Control and Prevention is free to conduct research into the causes behind gun violence, according to a new government spending bill unveiled Wednesday evening.

The $1.3 trillion bipartisan measure clarifies that language Congress has renewed annually for the last two decades does not preclude the country's premier public health agency from researching firearms.

The omnibus spending measure, if passed, would not eliminate the language, known as the Dickey Amendment, outright. But it does notably clarify the intent behind the provision, which critics say has had a chilling effect on firearms-related research at the CDC.

“Vehicle,” the Phrase of the Week by James Salzer. Video by Bob Andres / bandres@ajc.com

"While appropriations language prohibits the CDC and other agencies from using appropriated funding to advocate or promote gun control, the Secretary of Health and Human Services has stated the CDC has the authority to conduct research on the causes of gun violence," lawmakers said in agency instructions accompanying the spending bill.

First passed in 1996 following heavy lobbying by the National Rifle Association, the Dickey Amendment directs the CDC not to “advocate or promote gun control.” Researchers fought the decision initially – they argued they were never pushing for gun control in the first place – but work within the CDC’s $2.6 million firearms research program stopped shortly thereafter.

President Barack Obama ordered the CDC to conduct research following the Sandy Hook massacre in 2012, but advocates said the initiative was not funded well enough to answer major questions, and fear lingered that Congress could retaliate.

The new omnibus bill does not specify how much money could or should go specifically to gun research, but it does propose setting aside $649 million for Injury Prevention and Control work, more than double the current level. That category of spending includes domestic and sexual violence work, research into traumatic brain injury and opioid overdose prevention.

Gun control proponents cheered the news. U.S. Rep. Hank Johnson, D-Lithonia, said such firearms research “will produce data that will enable lawmakers to make better decisions and produce more enlightened policy that improves public safety in America.”

Lawmakers are expected to approve the bill by the end of the week. The government will shut down on Friday evening if Congress does not approve an additional spending measure.

Congress has been under immense pressure to act on guns and school safety in the five weeks since a gunman killed 17 at a Parkland, Fla., high school.

The spending package also includes a bipartisan measure seeking to boost information sharing among federal agencies through the FBI’s National Instant Criminal Background Check System, as well as a bill that would reauthorize $50 million annually in federal grants for school security efforts.

Staff writer Ariel Hart contributed to this article. 

Read more: Gun research may return at CDC decades after NRA pressure shut it down