NASHVILLE (AP) — Tennessee's attorney general says a transgender bathroom bill that is moving through the state Legislature could put the state's federal education funding at risk. If he's right, it could jeopardize more than $1.2 billion in federal money for K-12 and higher education.

The opinion issued Monday by Attorney General Herbert Slatery gives a dire warning about a controversial piece of legislation that is already getting backlash from the business community, Democratic lawmakers who oppose the bill said.

"I think if there was any further need to address this bill to recognize that it's the wrong road for Tennessee, the Attorney General's opinion should be the final nail in the coffin," said Rep. House Democratic Caucus Chairman Mike Stewart of Nashville.

The bill would require students in public grade schools and universities to use bathrooms and locker rooms that match their gender at birth.

If the measure goes on the books, federal education officials could view it as a violation of Title IX, a federal law that makes it illegal for schools to discriminate based on sex, Slatery's opinion said.

"As a general rule, if a state agency such as a public school or institution of higher learning directly or indirectly receives federal financial assistance and conducts an education program or activity that benefits from this assistance, the state agency must comply with Title IX throughout the operations of its entire agency," the opinion said.

The opinion noted that the federal Department of Education had already interpreted the law to include transgender students. And while that interpretation might change in a different presidential administration, the opinion said, state officials should assume that it may not.

Tennessee Gov. Bill Haslam has previously raised concerns that the state could lose federal funds if the bill passed.

Stewart and Rep. John Ray Clemmons, D-Nashville, said that in addition to the loss of federal funding, the state could lose lots of business.

In several states, major businesses and sports organizations — including Coca-Cola, Delta Air Lines, Walt Disney Co., the NFL and the NCAA — have joined lesbian, gay, bisexual and transgender activists in raising concerns that similar measures could legalize discrimination. CMT, the Nashville-based cable station that features country music videos and other TV entertainment, and parent company Viacom have come out against the bill.

Sen. Mike Bell, R-Riceville, and Rep. Susan Lynn, R-Mount Juliet, are the primary sponsors of the measure. Both were voting on legislation Monday and unavailable for comment.

However, the leader of a socially conservative organization blasted Herbert's opinion, saying it ignored two court cases that could be used to support the Tennessee's legislative proposal.

"The people of Tennessee are tired of having their public policies being dictated to them by the various branches of the federal government, and they sure don't want the state surrendering without a fight to the Obama administration on whether boys can choose to use a girl's bathroom or locker room," David Fowler, president of Family Action Council of Tennessee, said in an email to supporters.