However, his old colleague Sir Richard Greenbury, who as M&S boss took profits through the£1 billion barrier, insisted that the store group could rise again.
'My feeling is one of sadness that is has come to what it has,' Sieff said. 'I would love to have said the people who took over had done a fantastic job. I feel terribly sorry for staff and customers. The principles of the business have been totally forgotten.' He said there had been 'too many egos at play in the boardroom'.
Sieff, the last family member to occupy a seat on the board, stepped down in 2001. He said he did not care who ran M&S, as long as the business was returned to the public's affections. 'Whoever could do it, should do it,' said Sieff.
Greenbury maintained one of M&S's greatest strengths remains its wide appeal - 'from miners' wives to the wealthy' - and breadth of offer, from food to fashion.
He said: 'Any business that can sell£8 billion of goods in a year, that has a leading clothing market share and managed to sell goods at a price that generated profits of£760 million must be doing something right.
'If it is well managed then that£760 million can go back towards£1 billion. A few good decisions will push it back up.'