Standfirst: Sainsbury’s exploratory talks with Morrisons matter less because a deal is imminent than because the competitive map has changed since the CMA blocked Sainsbury’s and Asda in 2019. The discounters are now part of the mainstream market the regulator is policing.
The most important thing about reported merger talks between Sainsbury’s and Morrisons is not whether they restart.
It is how different the British grocery market looks from the last time Sainsbury’s tried to do a transformational deal.
Sky News reported this week that Sainsbury’s held exploratory discussions with Morrisons earlier in 2026. No transaction has been announced and there is no certainty that talks will resume.
But the possibility is revealing because it arrives seven years after the Competition and Markets Authority blocked Sainsbury’s proposed merger with Asda. In 2019, the regulator concluded that combining the two would reduce competition and could mean higher prices, poorer quality and less choice.
The structure around that decision has now shifted.
The discounters are no longer on the edge of the market
Government grocery statistics based on Kantar data put Tesco at 28.2 per cent of the UK market in the 12 weeks to 17 May 2026, Sainsbury’s at 15.2 per cent, Asda at 11.5 per cent, Aldi at 10.8 per cent, Lidl at 8.6 per cent and Morrisons at 8.3 per cent.
That means Aldi and Lidl together accounted for 19.4 per cent of the market in that snapshot, more than Sainsbury’s on its own and comfortably ahead of the old idea that discount chains sat outside the mainstream supermarket system.
The CMA has effectively acknowledged the same transformation.
When grocery land rules were introduced in 2010, Aldi and Lidl were excluded because they were considered limited-assortment discounters. In August this year, the CMA provisionally decided that both should now be treated as Large Grocery Retailers, subject to the same restrictions designed to stop major supermarkets using land agreements to block competitors.
That regulatory shift is easy to overlook. It is also one of the clearest signs that the market has changed category.
Competition policy follows consumer behaviour
Regulators do not assess mergers by counting logos. They assess how consumers actually shop, how closely businesses compete, what happens locally, how suppliers are affected and whether a deal is likely to reduce meaningful choice.
In 2019 the CMA explicitly considered competition from Aldi and Lidl and still concluded that the Sainsbury’s-Asda deal should be blocked.
Seven years later, the discounters are larger, carry broader ranges, operate nationwide networks and are being brought inside rules once reserved for the traditional giants.
That does not mean a Sainsbury’s-Morrisons combination would be waved through. It means the competitive evidence would be different.
And that is the second-order story.
The supermarket has become a network business
Scale in grocery is about much more than headline market share. Store locations determine convenience. Warehouses and delivery networks determine online economics. Procurement scale affects supplier negotiations. Loyalty schemes create customer data. Private-label ranges influence margins and differentiation.
A merger can therefore create efficiencies and bargaining power at the same time as raising legitimate concerns about local competition and supplier concentration.
That tension will define any future round of consolidation.
Traditional chains face intense price pressure from Aldi and Lidl, rising operating costs and increasingly expensive store estates. At the same time, consumers expect low prices, convenient locations, strong own-label ranges, rapid delivery and personalised promotions.
Those demands reward scale.
But scale can also weaken competition if too many local choices, supplier relationships or distribution networks end up controlled by too few groups.
The “big four” label has outlived the market
For years, Britain talked about Tesco, Sainsbury’s, Asda and Morrisons as if they were a fixed competitive set.
That framing is now less useful than it once was.
Aldi and Lidl have not simply taken share from the traditional grocers. They have changed what counts as a full-scale supermarket competitor. Their rise has altered pricing expectations, store formats, private-label strategy and now the regulatory map itself.
That matters for investors, suppliers and shoppers because the next supermarket merger will not be judged against the market of 2019.
The interesting question is no longer whether Britain still has a “big four”. It is whether the next version of grocery competition produces enough scale for retailers to stay efficient without giving consumers and suppliers too few meaningful alternatives.
That is a harder question than counting supermarket brands, and it is the one any future Sainsbury’s-Morrisons deal would have to answer.
Sources and verification
- Sky News, October 2026: authoritative report that Sainsbury’s held exploratory merger discussions with Morrisons earlier in the year.
- UK Government food statistics: Kantar-based grocery market shares for the 12 weeks ending 17 May 2026.
- Competition and Markets Authority, 7 August 2026: provisional decision that Aldi and Lidl should be designated Large Grocery Retailers under controlled-land rules.
- Competition and Markets Authority, 25 April 2019: final decision blocking the proposed Sainsbury’s-Asda merger.
- City A.M., 7 October 2026: originating lead reviewed for this article.
