One day after a mass shooting in Milwaukee that left at least six people dead, Gov. Bill Lee will announce his support for legislation that would make Tennessee the latest state to allow residents to carry guns without obtaining a permit.

The governor is expected to make the announcement Thursday morning, according to four people with knowledge of Lee's plans. The legislation is expected to allow Tennesseans to freely carry weapons in the open or concealed.

While showing his support for permitless carry, the governor is expected to announce plans to update the penalties for those who use guns illegally.

Lee’s sudden embrace of what is often called permitless gun legislation comes as lawmakers have considered a multitude of gun-related bills this session.

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The move, which would place Tennessee in the minority of states to embrace such a system, has long been eyed by Second Amendment advocates. Other states to embrace permitless carry include Alaska, Arizona and Arkansas.

In the past, permitless carry legislation — often referred to by advocates as constitutional carry — has been defeated in legislative committees, with top Republicans and law enforcement officials preferring to utilize the state’s current permitting system.

But since Lee entered office last year, lawmakers have made several moves to upend the permitting system, including approving a law to create an alternate option that allowed residents to obtain a gun by taking an online course.

Lee’s forthcoming announcement signals a significant divide from his predecessor, former Gov. Bill Haslam. When a permitless carry bill was considered in 2016, members of Haslam’s administration, including the head of the Tennessee Highway Patrol, opposed the measure, which was defeated in committee.

Lee's decision is all but assured to please his Republican base, which in recent months has challenged him on everything from refugee resettlement to paid family leave for state employees.

The move is in step with another decision by Lee earlier this session, when he said he would introduce a comprehensive set of abortion restrictions that would place Tennessee at the forefront on the issue. The administration has yet to introduce language of the abortion bill, which was met with criticism by advocates for the right to an abortion and Democrats.

Likewise, Democrats could easily seize on Wednesday’s mass shooting at the Molson Coors Complex to criticize the governor’s permitless carry proposal.

But with Republicans maintaining a supermajority in both legislative chambers, the governor's decision to back the gun legislation all but assures its passage, unless GOP members are divided.

The governor is expected to be joined by several Republican lawmakers when he makes his announcement Thursday morning.

Natalie Allison contributed to this report.

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Reach Joel Ebert at jebert@tennessean.com or 615-772-1681 and on Twitter @joelebert29.