M&S's profits were almost wiped out after it was hit by a cyber-attack which left shoppers unable to buy online from the company for months.
The hack was "an extraordinary moment in time," it said, as it revealed statutory profit before tax - a figure that reflects all costs for a period - slumped 99% from £391.9m to £3.4m for the first half of the year, compared with the year prior.
As well as disrupting its online business, the hack affected M&S in-store too, leaving some shelves bare in the weeks after it was targeted.
M&S's boss said profits should recover in the key Christmas period, but warned a later Budget and chancellor's speech on Tuesday had not inspired confidence in UK shoppers.