A coalition of prominent gun control, teacher and civil rights groups is threatening legal action against the Department of Education if it moves forward with a controversial proposal that would allow states to spend federal funds on guns for school personnel.

"We are extraordinarily concerned with this dangerous, and what we believe to be unlawful, proposal under consideration to supply teachers with federal funds to buy gun for their classrooms, instead of books and school supplies," said Giffords Law Center chief counsel Adam Skaggs, whose group, which was co-founded by shooting victim and former Rep. Gabby Giffords, is taking the lead on the potential suit.

Other members of the coalition are the American Federation of Teachers, the second-largest teachers' union; the Southern Poverty Law Center; and Democracy Forward, a nonpartisan legal group targeting executive branch overreach.

NBC News reported this week that Education Secretary Betsy DeVos began deliberating the controversial move earlier this year after Texas and Oklahoma asked the agency if schools could buy weapons using federal funds known as Student Support and Academic Enrichment grants, which are part of Title IV funding. The Education Department is still weighing the issue and "no decision is imminent," a senior administration official told NBC.

But if the agency moves forward with the proposal, the coalition is prepared to fight it.

"In essence, our complaint will seek a declaration that allowing these federal funds to be spent on guns instead of activities meant to make schools feel safe is unlawful, as well as an order from the court enjoining the Department of Education from approving such funds," Skaggs told NBC News.

Skaggs explained that the suit is based on the fact that "nowhere in federal law has Congress authorized the use of education funds for the purchase of guns or to arm teachers."

Citing the Gun-Free School Zones Act of 1990, which bans unauthorized individuals from bringing loaded and unsecured guns into school zones, as well as the definition of school "drug and violence prevention" under federal law (it includes the phrase,"the creation and maintenance of a school environment that is free of weapons"), Skaggs said federal law "in various ways makes clear" that "guns are disfavored in the education environment."

The Education Department did not immediately respond to a request for comment.