Marks & Spencer was reported today of demanding bigger price discounts from its suppliers, only a couple of weeks after its sales fell.

It is understood that M&S met its top 10 suppliers – including Northern Foods, Uniq and Bakkavör – last week to unveil the changes. The crackdown is thought to be known internally as Project Genesis.

Demands include a 2 per cent discount on all bills and additional discounts of up to 3.5 per cent, depending on how much it sells. The contribution towards marketing and advertising expenditure is being increased from 0.5 per cent of the total bill to 1.5 per cent.

One source told the Daily Mail: “They are demanding up to 6.5 per cent off the price. This is unsustainable for many of us – our profit margins are only about 7 per cent. Everyone has already given them up to 5 per cent (off rates) during the past two years.”

An M&S spokesman said: “We’ve been looking at doing this for some time. We have seen a significant growth in food over two to three years and our suppliers have benefited from increased sales.”

In the quarter to December 29, M&S reported underlying food sales were down 1.5 per cent and sales of clothing and household goods were down 3.2 per cent. Trading is understood to have weakened further since then.