The UK Competition and Markets Authority (CMA) has ordered supermarket chains Sainsbury's and Asda to stop blocking rivals from opening stores nearby.

The regulator said that the two retailers breached the Groceries Market Investigation (Controlled Land) Order 2010 multiple times between 2011 and 2019.

Sainsbury's breached the order 18 times during this period while Asda did it 14 times.

According to the CMA, this illegal practice reduces consumer choice of groceries and access to lower prices,

CMA markets and mergers executive directors David Stewart said: “Restrictions of this nature are against the law, cause real harm to shoppers and will not be tolerated. This is particularly important at a time when many families are struggling to pay their weekly grocery bills.

“This enforcement action today is part of our wider action to tackle the cost of living and ensure that families really benefit from more competition.

“We recently stepped up our work to assess whether any failure in competition is contributing to grocery prices being higher and we will be updating on this next month.”

In response to CMA’s order, Sainsbury’s agreed to remove the restrictions from its land agreements.

Asda also removed restrictions identified by the regulator from its land agreements.

The BBC quoted an Asda spokesman as saying: "We have reviewed details of over 1,600 property-related transactions, which identified 14 issues. All of these relate to legacy transactions that occurred between 2011 and 2019, when Asda was under different ownership and involve technical errors in documentation that have all been resolved.

The move is part of CMA’s specific programme of activity to implement the Order’s rules on land agreements.

The regulator issued a similar order against Tesco in 2020 and Waitrose in September last year.