Marks & Spencer chief executive Sir Stuart Rose may be forced to step down or resign after yesterday’s shock profit warning wiped £1.2 billion off the value of the retailer.

In a note issued this morning, Pali International analyst Nick Bubb said Rose’s “judgement and credibility” was being “actively called into question” following the update, which revealed that like-for-like sales fell 5.3 per cent in the 13 weeks to June 28.

Bubb said the AGM vote next week on Rose’s election as executive chairman “could be ugly and there is probably a 40 per cent chance that, in due course, he will be forced to step down or resign”.

He added: “That will leave M&S in even more of a mess than it is at the moment, given the lack of an obvious successor. Even if Rose clings on to power, his authority will be much weakened.”

Credit Suisse analyst Tony Shiret said: “Regrettably, we feel that the credibility of senior management has been irreparably damaged by both the degree of profit erosion in what was meant to be a relatively defensive company since Christmas and the lack of any clear idea from management that they have a grip on the problems.”

He added that another profit warning this year was possible and could lead to calls from shareholders for Rose to step down.

Shares in M&S fell 25 per cent to an eight-year low of 250p.