The 30-plus lawyers who recently left Washington law and lobby firm Patton Boggs include a high-profile D.C. lobbyist and antitrust attorney, and much of the firm’s health and safety practice group.

Jonathan Yarowsky, a lobbyist and antitrust attorney, has joined WilmerHale, where he is leading the firm’s legislative affairs and public policy practice. WilmerHale is recognized primarily as a regulatory law firm, not a premier lobbying firm, but Yarowsky said he plans to help expand the firm’s lobbying outreach to Congress and the White House. Yarowsky was previously White House counsel on antitrust, telecommuncations and crime policy during the Clinton administration, and also served as general counsel of the House Judiciary Committee.

He said his move to WilmerHale was in the works for more than several months, and unrelated to the recent loss of 24 energy attorneys in Patton Boggs’s Dallas office, who left recently to join Holland & Knight. He said he is still working out details about which clients will follow him to Wilmer.

Meanwhile, the majority of Patton Boggs’s health and safety practice group has joined employment law firm Jackson Lewis, and will be taking most of their business with them. Six health and safety lawyers, including the group’s lead partner Henry Chajet, have left Patton Boggs’s Denver and Washington offices and started work at Jackson Lewis earlier this month. Joining Chajet are former Patton Boggs partners R. Brian Hendrix, Robert Horn and Mark Savit, of counsel Avidan Meyerstein and associate Donna Vetrano Pryor.

At least 33 attorneys, including 19 partners, have left Patton Boggs in the past month. It is not unusual for partners who generate significant business, known in the legal industry as “rainmakers,” to jump to a new firm on their own or with a small group of colleagues. However, it often means a sudden loss of revenue for the firm they are leaving, especially when the departing lawyers make up most or all of one practice group. A Patton Boggs spokesman did not return a request for comment.

“We brought over a critical mass of our partners,” Chajet said. “It’s the vast majority of the team and the vast majority of clients are following us over. We expect 95 percent of our client base to join us here.”

Chajet said his group was not among the Patton Boggs partners who were asked to improve productivity late last year, and that his group, like the partners in Dallas, were highly profitable.

Prior to the addition of the Patton Boggs group, Jackson Lewis had about 25 attorneys who practice health and safety law, representing companies in a broad range of workplace safety issues including enforcement of federal regulations and investigations by federal agencies into workplace accidents. The Patton Boggs team brings new specialized expertise in mine safety, chemical safety, construction and manufacturing, said Jackson Lewis chairman Vincent Cino.

In March, Patton Boggs laid off 65 attorneys and staff.