M&S expects cyber-attack to last into July and cost £300m in lost profits

M&S customers have been ‘unwavering in their support’ since the cyber-attack, Stuart Machin said. Photograph: Neil Hall/EPA

Marks & Spencer has said it will take an estimated £300m hit to profits this year from a damaging cyber-attack that it expects to disrupt its online business into July.

Its chief executive, Stuart Machin, confirmed that “threat actors” had gained access to the retailer’s systems via one of M&S’s contractors using “social engineering” techniques, which can include posing as a staff member to fool a helpdesk.