The opinion is in reference to bill SB0202 sponsored by Sen. Bill Ketron, R-Murfreesboro, that would impose a $10,000 fine on employers who are found to hire illegal immigrants.
The bill is scheduled for a Senate floor vote Monday and is scheduled to be heard Wednesday by the House Finance, Ways and Means Committee.
Cooper's opinion, which was released Friday, cites a federal law which explicitly states federal immigration law "pre-empts any state or local law imposing civil or criminal sanctions" on those who recruit or hire illegal immigrants.
"SB202, if enacted, would do just that, running afoul of Congress' clearly stated intent to occupy the field in this area of immigration regulation," the opinion states.
Cooper's opinion may also apply to another bill filed by Ketron and awaiting both Senate and House floor votes. That bill would allow local law enforcement agencies to enforce immigration law in Tennessee.
A note on the bill filed by the Legislature's Fiscal Review Committee says the bill is invalid and cannot be enforced because of the federal pre-emption.
In April, the Senate passed an immigration bill that would require Tennessee employers to check a federal database to make sure a prospective employee is a legal resident of the United States.
But that bill was amended, with the approval of sponsoring Sen. Jack Johnson, R-Brentwood, to eliminate any penalty for employers who violate the law. It also would automatically be repealed in 18 months after taking effect.
The bill is scheduled to be heard Wednesday by the House Finance, Ways and Means Committee.
A bill that prohibits transportation of illegal immigrants into Tennessee for profit is awaiting the signature of Gov. Phil Bredesen.
Sen. Tim Burchett, R-Knox- ville, who sponsored the bill with Rep. Mike Turner, D-Nashville, said his bill is valid because it targets the individuals who bring illegal immigrants into Tennessee and not the immigrants or employers.
The bill imposes a $1,000 fine on offenders for each illegal immigrant transported.
"A serious issue has arisen because a group known as â€˜coyotes' are taking advantage of people by requiring them to pay large sums of money, then packing them in a vehicle like cordwood, and then transporting them long distances," Burchett said. "This practice is not safe for the people being transported, and it is not fair for the residents that are here legally."