"It is clear that there has been a material shift in trade and whilst it is too early to predict with precision where a new post-COVID sales mix will settle, we must act now to reflect this change," M&S said.
Clothing and home trading in its stores remained well below last year though online and home delivery were strong, said the retailer, which has a UK workforce of about 78,000.
The 136-year old M&S is seeking to reinvent itself after decades of failed attempts. In May it said the crisis would indelibly change its business and that it would accelerate its turnaround plan.
M&S said the crisis had shown it could work more flexibly and productively with more employees multi-tasking and switching between the food and clothing and home divisions. Its use of technology has also increased.
Last month M&S shed 950 store management jobs. Its latest cuts will impact its headquarters, regional management and UK stores over the next three months.
The cuts add to thousands already announced by other major British retailers, including Boots, John Lewis [JLPLC.UL], Dixons Carphone and WH Smith.
M&S expects a significant proportion of its cuts to be through voluntary departures and early retirement. Shopworkers' trade union Usdaw called for urgent talks.
"These proposals are an important step in becoming a leaner, faster business set up to serve changing customer needs," CEO Steve Rowe said.
M&S shares were down 2.8% at 0818 GMT, extending 2020 losses to 48%.
The firm said it was retaining a cautious approach to planning for the balance of the year.
Group sales were down 19.2% year on year in the 19 weeks to Aug. 8, which included part of Britain's lockdown period, with clothing and home sales down 49.1% and food sales down 1.1%.
Clothing and home sales were down 29.9% in the eight weeks since stores reopened. Store sales were down 47.9%, while online sales were up 39.2%.
Food stores, which traded throughout the lockdown period, saw sales increase 2.5% in the latest eight weeks.
M&S said it was on track to launch an online food service next month through its partnership with Ocado.
By James Davey