Marks & Spencer is carrying out a major review of its buying department in a move that will affect 40 buyers, at least six of whom will lose their jobs.

The retailer was rationalising its headcount in response to tough trading conditions, said a manufacturer supplying the company, who condemned the game of "musical chairs".

"Between 30 or 40 people are on notice and will have to reapply for their jobs," he claimed, warning that the move was a sign M&S would continue to toughen its stance on suppliers as well.

"Other retailers have done this in the past but if they treat their own employees like this, it is an indication of what suppliers can expect," he said.

M&S confirmed it was "combining a small number of buying roles to avoid duplication", but denied buyers would have to re-apply for their jobs. It was in a period of consultation that it was legally obliged to undertake, it said.

"We are making changes to be more closely aligned to the needs of the business," said an M&S spokeswoman. "We hope to have the new structure in place in May."

Redundancies were a

possibility, she admitted, but the retailer hoped to place those who lost their jobs in other roles in the company.

Suppliers expressed concern about the ramifications for their businesses. M&S had already started turning the screw, claimed one, and was now "just as harsh as anyone else".

"With other retailers you expect to get a kick between the legs, but because of the brand values of Marks & Spencer, it has been a surprise," he said.

Earlier this year, The Grocer revealed details of Project Genesis, M&S's new food and drink trading terms, which included an across the board 2% cut in prices paid to suppliers, a 1.5% marketing charge and possible further cuts of up to 3.5% depending on sales growth with the retailer.

At the time, Sir Stuart Rose claimed the terms were "perfectly reasonable".

"I do not believe there is any issue where a supplier will be worse off having done more business with us. If there is such a case clearly we wouldn't ask them to do that," he said.