Bill McMorris documents for the Washington Free Beacon a disturbing case of union-thug tactics.

A Michigan union fired back at workers who dropped off the membership rolls by urging its members to isolate them at work.

Jeff Hagler, president at UAW Local 412 in Warren, Mich., sent out a newsletter to about 3,000 autoworkers who belong to the union in December. The letter includes a list of 43 mostly female workers who opted out of membership, as well as advice on how they should be treated in the workplace.

“They have elected to quit paying union dues, but are still benefitting by continued representation by the union. Whether we feel this is fair or not, it is permitted to happen because of this continued attack on unions,” he said in the letter, which was first obtained by Michigan Capitol Confidential. “Please do not share any tools, knowledge or support for any of these employees who choose not to pay their fair share.”

Hagler did not respond to request for comment.

Local 412’s advocacy for isolating co-workers could hurt the union’s cause, said Vinnie Vernuccio, a labor expert at the Mackinac Public Policy Center, a Michigan free market think tank.

“The UAW is possibly jeopardizing workplace safety by advising its members to not share tools, knowledge, or support with employees on the list, the exodus will likely only grow,” he said. “The UAW is simply trying to bully and intimidate former members who exercised their rights. The tactic is backfiring as every time the union publishes the list, it only grows.”