An independent review has rejected the forced break-up of Coles and Woolworths, finding the “populist” idea, backed by the Coalition and advocated by the Greens, lacked “credibility” and could trigger store closures and job losses.

The review by economist Craig Emerson instead proposed supermarkets and suppliers abide by a mandatory code of conduct backed by stiff penalties of up to $5.2 billion for the largest chains.