The closures will affect its clothing and home stores, which have under-performed for several years.
M&S named 14 stores earmarked for closure on Tuesday, including in London’s Bayswater and Holloway Road, with a total of 872 employees affected.
The move is part of a five-year turnaround plan spearheaded by chairman Archie Norman and chief executive Steve Rowe.
They have been seeking to save costs through store closures and shutting distribution centres as part of a wide-ranging efficiency drive as the company’s financial performance deteriorates.
Sacha Berendji, retail and property director at M&S, said: “We are making good progress with our plans to reshape our store estate to be more relevant to our customers and support our online growth plans.
“Closing stores isn’t easy but it is vital for the future of M&S. Where we have closed stores, we are seeing an encouraging number of customers moving to nearby stores and enjoying shopping with us in a better environment, which is why we’re continuing to transform our estate with pace.”
Bayswater, Fleetwood Outlet in Lancashire and Newton Abbot Outlet in Devon will close by the end of July 2018. Clacton in Essex and Holloway Road will both close by early 2019.
Darlington, East Kilbride, Falkirk, Kettering, Newmarket, New Mersey Speke, Northampton, Stockton and Walsall are proposed for closure and will now enter a period of consultation with affected employees.
The announcement comes a day before the retailer is expected to unveil another troubling set of annual figures.
Wednesday’s results are set to show that underlying pre-tax profit across the group fell 6% to £573 million.