The shadow chancellor of the exchequer in the British Parliamentary system is the member of the Shadow Cabinet who is responsible for shadowing the chancellor of the exchequer. The title is given at the gift of the leader of the Opposition and has no formal constitutional role, but is generally considered the second-most senior position, unless a shadow deputy prime minister is chosen, on the opposition frontbench, after the leader. Past shadow chancellors include Harold Wilson, James Callaghan, Edward Heath, Geoffrey Howe, Kenneth Clarke, Gordon Brown, John McDonnell and Rachel Reeves.