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 The Plaza, East Kilbride and the High Street in Falkirk, with a total of 872 employees affected.
The announcement comes a day before the retailer is expected to unveil another troubling set of annual figures.
Full list of Marks and Spencer stores across the UK proposed for closure:
The Plaza, East Kilbride
High Street, Falkirk
Fleetwood Outlet, Lancashire
Newton Abbot Outlet, Devon
New Mersey Speke