JD Sports Fashion has criticised the competition watchdog for paving the way for potential job losses after the retailer was blocked from merging with a struggling rival, Footasylum.

Peter Cowgill, the executive chairman of the UK’s largest sports retailer, said the company “fundamentally disagreed” with the Competition and Markets Authority’s decision, which was “absurd” in the light of the high street’s struggles.

JD, which owns a string of sports and outdoor-wear chains including Blacks, Go Outdoors, Millets and Spain’s Sprinter, as well as JD Sports, said it was considering whether to appeal against the ruling, which will require it to sell off Footasylum just over a year after acquiring the chain for £90m.

JD said Footasylum may have disappeared from the high street without its financial backing, and any new owner would probably cut jobs at the struggling chain.

Cowgill said: “We fundamentally disagree with the CMA’s decision, which continues to rely on an inaccurate and outdated analysis of the UK sports retail competitive landscape, and is underpinned by outdated and flawed customer surveys.”

In a veiled reference to Mike Ashley’s Sports Direct, he added: “Incredibly, the CMA has been taken in by the self-serving testimony of one notoriously vocal competitor, who has made numerous public announcements.” He said that competitor had “blatantly participated in the process for their own commercial interests rather than for the benefit of consumers”.

The CMA said it was blocking the merger as it would lead to a “substantial lessening of competition in sports-inspired casual footwear and apparel products sold both in stores and online. As a result, shoppers would be worse off.”

It said JD should sell Footasylum and that the coronavirus lockdown, which has forced both companies temporarily to close all their outlets, should not make any difference to its decision.

But the regulator left some room for manoeuvre should high street closures bring about further changes in the market. “There is flexibility in our remedies implementation process, which means we can respond to any relevant developments throughout the sale process,” the CMA said.

Cowgill said the CMA’s year-long investigation had failed to take into account significant changes in the market, with the coronavirus outbreak forcing trading to move exclusively online, and intensified competition.

He said trade would likely be slow for high-street stores even once the lockdown was eased.