Comment: Justin King leaves a great legacy at Sainsbury's, says Bryan Roberts

The ink’s still barely dry on the press release and the rumour mill is already in overdrive. Where is Justin King off to?

Is he leaving Sainsbury’s at a peak before a deceleration takes hold? Will it turn out to be a Leahy-style hospital pass? Will Mike Coupe take on the reins before elevating Sainsbury’s to new heights? Or will it be a Fergie/Moyles style transition that will lead to Sainsbury’s being outflanked by nimbler competitors with deeper pockets?

Either way, there can be little doubt that King leaves Sainsbury’s in an infinitely better position than he found it. Although it lags Tesco/One Stop by a country mile, the Sainsbury’s Local estate is extensive and puts the retailer firmly in the ongoing sweet spot of convenience retailing.

Online, the profitability of which remains shrouded in a degree of mystery, has progressed incredibly well during the King tenure. The retailer’s private label portfolio is among the best in the business and the company’s (belated) assault on the non-food market has been both rapid and delivered with no small measure of panache.

Other highlights include the implementation of Brand Match, which represented a real step change in the value perception of Sainsbury’s, some very decent marketing campaigns over the years and laudable positions in areas such as Fair Trade, horsegate, general provenance and the environment.

Simply put, King inherited something of a basket case and has re-established Sainsbury’s as a world class operator that has deservedly trounced some of its rivals in terms of like-for-like growth and market share gains in recent years.

There is still work to do. The business will have to work, and spend, harder to narrow the convenience gap with Tesco. There is still a yawning chasm in click-and-collect grocery where Asda and Tesco are running riot. Despite recently overcoming the ‘less profitable than Morrisons’ brickbat, there is still a significant differential in margins compared to rivals. Coupe has the pedigree and experience to take these challenges on, and he will, hopefully, retain around him a talented team to put the necessary strategies in place.

Whatever King does next, it is fair to suggest that the UK supermarket sector is losing one of its genuine success stories. Compelling, charismatic and with a great strategic mindset, King has done a blinding job at Sainsbury’s and leaves with a deserved place in the UK supermarket hall of fame.

It is a far cry from when I first met him, when he was wearing an alluring green polo shirt in the car park at the opening of Asda Walmart Patchway. How times change.

Bryan Roberts is insights director at Kantar Retail