William Miller, a partner in Brunswick Group’s Washington office, is joining the Business Roundtable as senior VP to oversee government relations.

The Roundtable, the respected business lobby composed of the CEOs of large U.S. corporations, has been led by former Michigan Governor John Engler since late 2010.

Miller, a D.C. restaurateur who co-owns Tackle Box and Hook in D.C., exits Brunswick after less than a year. He was previously senior VP for political affairs and federal relations at the U.S. Chamber of Commerce, where he frequently served as a media spokesman for the group.

Earlier, he was chief of staff to Rep. Constance Morella (R-Md.).

Following the Supreme Court decision on the Affordable Care Act June 28, the BRT, which provided tepid but crucial early support for healthcare reform in 2009, urged Congressional restraint. “With the health care law now upheld, policymakers should first carefully analyze and understand the implications of the ruling, and engage in an open dialogue with the American people about the best way to move forward,” the group said in a statement.

Politico, which first reported Miller’s move, said the BRT is beefing up its policy development and wants to have more input on the Hill ahead of a landmark lame-duck session after the November election.