Not even the slew of celebrity endorsements from the likes of model Twiggy and actress Dame Helen Mirren have been enough to raise womenswear sales.
But there have been some glimmers of hope. Fashionistas went mad for the mid-length suede skirt from M&S after it was worn by fashion celebrity Alexa Chung.
In 2015, the skirt was credited with helping to "jump start" the first profit rise for four years but not everyone was convinced.
The Guardian's Hadley Freeman claimed the skirt represented "a triumph of M&S PR over actual fashion for women".
For the past five years, clothing sales have been in an inexorable decline, but apart from the fashion what else is to blame?
Was it the weather? Marks and Spencer said its recent 5.8% drop in general merchandise sales - which include clothes - was due to "unseasonal conditions and availability".
It also claimed the weather was a factor in January 2015, when it said its 14th consecutive quarterly drop in clothing sales was down to unseasonal autumn weather.
Bitten from both ends
However, retail analyst Nick Bubb said: "You can't make excuses about the weather every year."
He says that one of the main problems has been that the retailer has been besieged, and bitten from both ends.
Discounters and budget chains have been taking market share from M&S at the lower end. Brands like Zara and H&M are taking a chunk out of the middle end of the market, while John Lewis has stolen a march on M&S at the higher end.
"If you want to be all things to all men - and all women - it's going to be an impossible task," he said.
M&S also has problems competing with certain chains on price versus quality. Barclays Capital analyst Christodoulos Chaviaras said the quality of M&S clothes is good, but people can get better value for money elsewhere.
The firm's focus on full price items while other retailers have discounted, also played a part in M&S's negative sales, he said.
And Mr Bubb says that Marks and Spencer has failed to keep up with the Joneses online - which is now the key battleground for retailers.
John Lewis started investing in online sales more than ten years ago, he says, and Marks and Spencer has been playing catch-up.
"Marks and Spencer has too high a share of a declining market - offline retailing - and too low a share of the online market."
Senior management must also examine its conscience, he adds.
"They [the board] have taken the decisions on branding and marketing, and they've been very late to the party [with online]," he said.
Making a comeback?
Many yearn for the retailer to succeed again, so what can M&S do?
Kirsty McGregor from fashion industry publication Drapers says: "There has been a good response to the last few seasons from the fashion press... what we're not really seeing is these styles and sizing options in the regional stores and customers find that quite frustrating."
Retail analyst Tony Shiret adds: "They need to decide where the gaps in their coverage are, improve the quality of their classic staple lines and continue to make progress with the fashion."
But be warned M&S, there is a troubling rival also striving for the title of national treasure.
"Unfortunately for them [M&S] John Lewis has stolen the crown as the retailer that everyone loves and trusts," Sali Hughes said. "They have become the well loved and dependable aunty on the high street.
"I don't think this is the end for M&S, they can turn it around. They just have to get back to what they were really good at."