In a defiant article published in John Lewis's company magazine, The Gazette, Sir Stuart says there will be no such sale under his chairmanship. He refers to recent speculation that the business will be floated as the result of "summer madness" and "a rather cruel dream based on false assumptions and raising false expectations".
Responding to pressure from John Lewis staff, who are referred to as "partners" in the department store and Waitrose supermarket group, Sir Stuart said that such a sale was impossible under the partnership's constitution.
"The fact is that the partnership cannot just be cashed in at the whim of one generation of partners," he says.
He said it was a myth that the company is a mutual organisation that belongs to its members in the same way as a building society.
"We talk about the business belonging to partners, but in fact the Partnership is owned in trust by John Lewis Trust Limited." The Trust was set up 70 years ago when John Spedan Lewis, son of the company's founder, handed over his ownership to make all staff beneficiaries in the company's profits.
Sir Stuart himself chairs the body, along with a deputy chairman and three trustees of the constitution, elected each year by the company's general council.
Sir Stuart claims it is untenable for partners to vote for a sell-off through a simple referendum since any break-up would require an Act of Parliament to change the terms of the trust.
"Spedan Lewis recognised human instinct and foresaw that in the future some partners might entertain just the thoughts which are now surfacing," Sir Stuart says.
And he warns: "I would have no hesitation in leading opposition to any action aimed at destroying the partnership and at contrasting the vision and generosity of Spedan Lewis's bequest with the short-sighted greed of carpet-baggers."
Sir Stuart also tries to convince his staff that their hopes of pounds 100,000 a head from the proceeds of a sale would not materialise even if a flotation did.
"Rich pickings might be on the table for lawyers, but for partners, the only certainty would be divisive debate."
John Lewis staff, or partners, will meet next month to debate a rewording of the company's 70-year-old constitution, which the management says will put the document into plain English, but which some see as a way for Sir Stuart and his allies to stop demutualisation. Some employees have also accused their bosses of censorship following their refusal to publish in The Gazette any letters that seek a referendum on the sale of the group.
Yesterday, John Lewis said its department store sales were up 15.3 per cent in the week to 7 August compared to the same week a year earlier.
Analysts put the value of the company at around pounds 3.9bn.
Outlook, page 17