Wesfarmers boss Rob Scott, retailer Gerry Harvey and Infrastructure NSW chair Graham Bradley have backed a national summit to jumpstart debate on tax reform, despite Treasurer Jim Chalmers dismissing the idea.

A day after the Business Council of Australia proposed to “break the malaise” of a flatlining reform agenda with a summit drawing in business, unions and the bureaucracy, Mr Chalmers poured cold water on the idea and insisted Labor had a “broad and expansive” reform agenda.