Tesco has said it stepped in to bail out rivals Marks & Spencer and some Co-op stores during their recent cyberattacks, sending extra branded stock via its wholesale arm Booker.

Chief executive Ken Murphy confirmed this week that M&S and several independent Co-op societies reached out for help after their supply systems went down, according to The Times.

“Over the period when they’ve been impacted, Booker has supplied both M&S and Co-op with products and supported them in any way they could,” Murphy said.

In M&S’s case, Booker reportedly increased deliveries of branded essentials like Marmite and Coca-Cola, while also ramping up direct shipments to stores.

Some independent Co-op societies, which are separate from the central Co-op Group, also turned to Booker to plug temporary supply gaps.

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The move has come as a surprise to many in the sector, as it highlights a rare moment of collaboration in a highly competitive supermarket industry.

Murphy was keen to stress the support was short-term, and that neither retailer’s supply issues had any material impact on Tesco’s recent sales.

M&S, which relaunched its website this week after nearly two months offline, has warned the hack could wipe £300m off its profits this year.

Despite this, the high street retailer said experienced a surge in online traffic after orders reopened, with many customers returning to baskets left full since April.

Meanwhile, Murphy said Tesco had not seen any “uptick in activity” following the attacks on its competitors, but he emphasised the ongoing cyber threat.

“Cybersecurity is at the top of my inbox on a daily, weekly basis,” he said. “As the sophistication of potential attackers improves, we have to keep investing behind it.”

Looking ahead, the CEO said Tesco has continued to upgrade its systems, and Murphy added the business works to “learn from what’s going on in the industry” to stay one step ahead.