The policy, originally "six pillars" (it initially included AMP and National Mutual), was adopted in 1990 by then Labor Treasurer Paul Keating. It covered the big four banks (Commonwealth Bank, Westpac, NAB, ANZ) and two insurers (AMP and National Mutual). It was essentially designed to block the merger between ANZ and National Mutual at the time. Keating believed this arrangement would ensure a competitive banking market.