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Looking lean and sharp in a Marks & Spencer blue and green check shirt, black jeans and designer white trainers, 55-year-old Stuart Machin bounds into his ninth-floor London office. We are in his company’s HQ and the word “Onwards” is boldly printed on a poster behind him.

This is what the M&S boss feels is the necessary direction of travel as he offers me sample slices of M&S Panettone (he found a family firm in Italy to make it). Pushing onwards is how he guided the firm and its 32 million customers through one of the worst-ever cyber attacks in the UK.

The cost to M&S has been around £300m, so regaining momentum for growth and profit is what drives him. “We set out three objectives – regain momentum, get back on track with growth and accelerate transformation. It is what we are doing, we are regaining momentum,” he says.

He calmly understates surviving the most damaging cyber attack in British high street history “The first half of this year was an extraordinary moment in time for M&S. However, the underlying strength of our business and robust financial foundations gave us the resilience to face the challenge and deal with it. We are now getting back on track.”

He refuses to dwell on the attack: “It’s in the rear view mirror now”. No one has yet been brought to justice over it, but he says a line has been drawn under it. “I’ve learned that you only have to be unlucky once and they have to be lucky once, but having put in the best cyber security, I have to concentrate on what is now best for our customers in the best cyber security.