Tory Burch is coming out swinging in her legal battle with ex-husband Chris Burch over her multibillion-dollar fashion empire.

She has hired prominent law firm Wachtell, Lipton, Rosen & Katz, which has hit many former employees of Chris’ C. Wonder with subpoenas, to be quizzed over whether, as she alleges in her suit, he “stole” any of her company secrets to make his “knockoff” brand.

In return, Chris has fired back with subpoenas for Tory’s brother Robert Isen, who is president of corporate development at Tory Burch, and his wife, Patty Isen, director of special projects at Anthropologie.

Other subpoena filings include one for Ager Miellier films, which created an ad spot for C. Wonder.

A source tells us, “Tory’s team has been issuing subpoenas to all former C. Wonder employees — including Scott Formby, who was creative director at C Wonder in the beginning. There’s been a lot of drama at the Wachtell, Lipton law offices.

“Chris’ team is scrambling with this latest subpoena. It shows that Tory is doing her homework and is reaching into the talent that put together the original C. Wonder concept. He is quite concerned . . . that she is going for the jugular. Things between them are spiraling downward.” Another source added, “Chris is hitting back with just as much force. This is becoming very bitter.”

The Post recently reported that Tory accused Chris of spying on her company while establishing a rival retailer — and of secretly developing a “financial relationship” with Russian-American billionaire Len Blavatnik, who placed an alleged “double agent” on her company’s board.

Chris Burch — who in an October lawsuit accused the Tory Burch label of blocking efforts to sell his 28 percent stake in the company for upward of $600 million — had “hundreds of communications . . . with Tory Burch employees in which he badgered them for, and received, inside information,” Tory Burch claims in court papers.

A rep for Tory Burch laughed and said, “The subpoenas are public documents.” Reps for Chris Burch didn’t get back to us.