UK supermarkets Sainsbury’s, Morrisons and Iceland have urged the Competition and Markets Authority to curtail Aldi and Lidl’s use of restrictive land clauses that keep rival stores at arm’s length. The trio argues that the 2010 Controlled Land Order was drafted when the discounters were niche players, not giants with nearly 20 % market share today.

Aldi, now the UK’s fourth‑largest supermarket, plans to open 40 new outlets this year, targeting 1,500 stores against 1,050 today, while Lidl, with over 1,000 sites, unveiled a wishlist of 100 new locations. Their rapid expansion has prompted rivals to accuse them of shaping local market economics through an unfair competitive advantage for consumers and retailers.

Iceland warns that the original distinction—narrow product ranges, lower prices and smaller stores—has eroded as mainstream chains trim offerings and cut counters. Morrisons notes that discounters now open larger formats, eroding its share of the big‑weekly basket and squeezing margins that once held the incumbent chain in the “Big Four” in the grocery sector that pressures investors.

A CMA consultation launched in March invites the regulator to re‑apply the 2010 rules, a move that could level the playing field and curb the discounters’ market dominance. The authority is expected to decide in September, a verdict that will shape the UK grocery landscape for years to come.