Why Britain’s competition watchdog believes Aldi and Lidl have outgrown the rules that once made them different
For years, Britain had a simple distinction in supermarket retail.
There were the big grocery chains — Tesco, Sainsbury’s, Asda, Morrisons, Co-op, M&S and Waitrose.
And then there were Aldi and Lidl.
The distinction was not simply about branding or prices. It was written into the regulatory framework.
When the Groceries Market Investigation (Controlled Land) Order was introduced in 2010, Aldi and Lidl were treated as “limited assortment discounters”. Their smaller ranges and different operating models meant they were not subject to the same land-agreement restrictions as the major supermarket groups.
Sixteen years later, the Competition and Markets Authority says that distinction no longer reflects reality.
And that is the real story behind its latest decision.
The regulator is saying the market has changed
The CMA is not simply changing a rule because Aldi and Lidl have become popular.
Its provisional decision is based on a broader argument.
The watchdog says Aldi and Lidl now have the scale and geographic reach of major grocery retailers, offer a full range of groceries and operate procurement models that put them firmly inside the category of large grocery retailers.
In other words, the CMA believes the supermarket market has evolved faster than the legislation.
The two German discounters are no longer fringe competitors operating at the edge of Britain’s grocery industry.
They are now among its biggest players.
The CMA has therefore provisionally decided that Aldi, Lidl GB and Lidl Northern Ireland should be brought under the Controlled Land Order.
What is the CMA actually trying to stop?
This is where the technical language becomes important.
The rules concern land agreements that can restrict rival supermarkets from opening stores nearby.
That can include arrangements such as restrictive covenants and exclusivity clauses.
The objective is relatively straightforward.
If a supermarket controls a strategically important piece of land, the regulator does not want that control to become a tool for preventing another supermarket from competing for customers in the same area.
The CMA’s position is essentially that consumers should have a choice.
If Aldi has a store in a particular area, another supermarket should not automatically be prevented from opening nearby simply because of an agreement attached to the land.
And the same principle should apply to Lidl.
Why now?
This is perhaps the most interesting question.
The CMA has known about the difference between Aldi, Lidl and the traditional supermarket groups for years.
What has changed is the size of the two discounters.
Aldi and Lidl have expanded from niche operators into national supermarket networks.
Their stores are now found across Britain.
Their product ranges have grown.
Their influence over supermarket pricing has grown.
And their ability to compete for prime retail locations has grown with them.
The CMA’s own assessment is that the original “limited assortment discounter” classification no longer fits.
That means the regulator is effectively updating the legal definition of what a major supermarket looks like.
This is not an anti-Aldi or anti-Lidl decision
That distinction matters.
The CMA is not saying Aldi and Lidl should stop expanding.
It is not ordering stores to close.
It is not accusing either company of breaking competition law.
And it has not said that the discounters’ business models are unfair.
Instead, it is saying that the same rules should apply to retailers that now occupy similar positions in the market.
That is a very different argument.
The CMA’s message is about equality rather than punishment.
If Tesco cannot use certain land arrangements to restrict competitors, the regulator believes Aldi and Lidl should not be able to do so either.
The supermarkets wanted this
The CMA has not arrived at this issue in isolation.
The question of Aldi and Lidl’s land agreements has been building for some time.
Major supermarket groups and other retailers have argued that the old framework created a regulatory gap.
That gap became increasingly difficult to defend as Aldi and Lidl expanded.
Responses published during the CMA’s review included submissions from Aldi, Sainsbury’s, Morrisons and Iceland, among others.
The pressure was therefore coming from inside the industry as well as from the regulator.
For competitors, the argument is simple.
If Aldi and Lidl are powerful enough to compete with the country’s largest supermarkets for locations and shoppers, they should also face the same restrictions.
But the CMA has a consumer in mind
The regulator’s strongest argument is not actually about supermarkets.
It is about shoppers.
The CMA says the proposed change is intended to give consumers the widest possible choice of where to shop.
That means the regulator is looking beyond the individual retailer.
A supermarket may have a perfectly legitimate commercial reason for securing land.
But if the result is that another retailer cannot enter the area at all, the CMA believes consumers can lose out.
The issue therefore becomes one of market access.
Who gets to compete?
And who gets locked out?
The land battle could become Britain’s next supermarket war
This could have consequences far beyond the legal documents.
Britain has limited prime supermarket space.
Good locations are valuable.
They have population density, parking, transport links and established shopping patterns.
The best sites can determine whether a new store succeeds or struggles.
If Aldi and Lidl can no longer use certain land arrangements to restrict competing supermarkets, those sites could become more contested.
Tesco may want them.
Sainsbury’s may want them.
Morrisons may want them.
Asda may want them.
And the discounters will still want them.
That could create a new battleground in British grocery retail.
Not just over prices.
Not just over promotions.
But over where the next supermarket gets built.
The regulator may have changed the balance — but not the winner
There is an important caveat.
Removing a property advantage does not automatically make a competitor more attractive to shoppers.
Aldi and Lidl have built powerful brands.
They have loyal customers.
They have developed highly efficient operating models.
And they have already demonstrated that they can compete successfully against the established supermarket groups.
Analysts have therefore warned that the proposed change is unlikely to suddenly reverse the discounters’ fortunes.
The CMA may be changing the conditions of competition.
It cannot decide which supermarket shoppers prefer.
That remains the retailers’ job.
The irony for the CMA
There is an interesting irony in the regulator’s decision.
Competition authorities generally become concerned when companies become too powerful.
But Aldi and Lidl’s success is also evidence that competition has worked.
They entered a market dominated by established players.
They disrupted it.
They forced competitors to react.
They gained customers.
And now the regulator is saying their success has become so significant that the rules must be adjusted around them.
The discounters have, in a sense, become victims of their own success.
The final decision is still to come
The CMA’s August announcement is provisional.
The consultation remains open until 7 September 2026, after which the regulator is expected to publish its final decisions in October.
So the story is not finished.
But the direction is already clear.
The regulator no longer sees Aldi and Lidl as special cases.
It sees them as major grocery retailers.
And that may ultimately be the most important message from this entire dispute.
The ISN View
The CMA has not declared war on Aldi or Lidl.
It has done something more significant.
It has effectively declared that the old definition of a supermarket no longer works.
Aldi and Lidl entered Britain as limited-range discounters.
Today, they are powerful national retailers capable of influencing prices, property markets and the strategies of their biggest competitors.
The CMA’s proposed rule change is therefore less about restricting the discounters than recognising what they have become.
The supermarket landscape has changed.
Now the rulebook is catching up.
And the next battle will be fought not in the regulator’s offices, but on Britain’s retail parks, high streets and supermarket car parks — where the question will be much simpler:
Who gets the next piece of land, and who gets the next customer?