Business groups say Labor’s sweeping industrial relations changes will lock in decades-old union conditions in workplaces and undermine the enterprise bargaining system championed by former prime minister Paul Keating as a path to productivity.

Workplace Relations Minister Tony Burke’s Closing Loopholes Bill No 2 includes a Greens measure that ensures unions cannot lose when a dispute becomes intractable and goes to arbitration, encouraging unions to refuse to bargain and to drag out disputes, business says.