The Competition and Markets Authority (CMA) is considering putting store planning restrictions on discounters Aldi and Lidl to ensure a “level playing field” across the UK grocery sector.

The competition watchdog is currently reviewing the Groceries Market Investigation (Controlled Land) Order, which looks to maintain competition between supermarkets by restricting major players from blocking nearby rival store openings, The Telegraph reported.

The order currently only applies to Tesco, Sainsbury’s Morrisons, Asda, Waitrose, M&S and Co-op. Aldi and Lidl are exempt, since they had a much smaller UK presence when the regulations first came into force in 2010.

The German discounters have since grown their UK estates rapidly, with Lidl owning more than 960 stores and Aldi more than 1,200 – taking them to a number comparable with Asda’s 1,100 stores and Sainsbury’s 1,400.

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Last July, Iceland executive chairman Richard Walker hit out at Aldi and Lidl over “restrictive” land deals that he claimed are “preventing competition on retail parks”.

Walker said that the German discounters are using “legal tricks” through property deal clauses that prevent competitors from opening stores within the same area. He urged the government to revisit the order.

He said at the time: “The German-owned supermarkets were just a twinkling in the CMA’s eye when this order was first made. Fourteen years on, and with the return of a Labour government, surely it is time to look at how the active use of these legal tricks is preventing competition on retail parks in towns across the UK.”

It is understood that the CMA has informed UK supermarket bosses that it is looking into the situation. Officials are now considering whether the rules should include Aldi and Lidl, or if the bans across the other seven British grocers should be removed.

A CMA spokesperson told The Telegraph: “The Groceries Market Investigation (Controlled Land) Order plays an important role in maintaining competition between supermarkets, which is crucial to the finances of families across the country.

“We are aware of concerns that the Order should cover more supermarkets, due to changes in the groceries sector, and we always keep this under review to ensure a level playing field.”