Data: M&S's biggest and smallest catchments for clothing and homeware spending

As well as exiting a tranche of markets overseas, M&S will also shutter 30 full-line stores in the UK, while around 45 more will either be downsized or converted into Simply Food shops.

The high-street bellwether is yet to reveal which stores it plans to close or convert.

As Rowe and his leadership team prepare to make some difficult decisions, new data from CACI has revealed the total clothing, furniture and homeware spend in the high streets and shopping centres where M&S has stores with a fashion and general merchandise offer.

While this is not an indication of which stores M&S will close, the bottom and top 15 catchments reveal how lucrative each shop could be in the fiercely contested fashion and general merchandise sectors.

According to the CACI data, shared exclusively with Retail Week, total spending on clothing, furniture and homewares is at its lowest on Merton High Street, where less than £5m is spent across the three categories annually.

Other catchments where M&S is present, including Longbridge in Birmingham, Sevenoaks, Milton Keynes and Kew Retail Park in Richmond, also fail to attract much in the way of general merchandise spend per annum.

All but one of the bottom 15 are given a D or E health rating by CACI, in which A is given to healthy, robust locations and E to smaller locations that are on the decline in terms of footfall and spend.

By contrast, London’s West End is the biggest catchment for fashion, furniture and homewares spending in which M&S currently has a general merchandise store.

The area rakes in more than £1bn in spend across the three categories every year, according to CACI data. 

Glasgow city centre is some way behind in second place with a £600m market, while Manchester’s Trafford Centre, Westfield’s two London malls and high-street locations in Leeds, Liverpool, Birmingham and Nottingham all make the top 15.

CACI consulting partner Paul Langston said: “The closures of the M&S stores across the UK will naturally be a strategic decision based on current performance and market potential.

“While these closures will be important for M&S in the future, in some locations they could be the final nail in the coffin for the centres in which the stores reside, as the ‘health’ of the retail spending in these locations continues to dwindle.”