Making sense of the past seven days
After the announcement last week that a private equity consortium was weighing up a bid for Sainsbury's, it's no surprise that various other names have been thrown into the ring.

Some - such as fellow private equity house Texas Pacific - were unsurprising, but by far the most intriguing name was Marks & Spencer, which was mooted as a potential bidder yesterday.

If it were to happen, it would be an extraordinary deal and would be a coup de grace with which Stuart Rose could really seal his transformation of M&S. What's more, it would reunite Justin King with the company where he did so much for its food operations.

The business created would unite two of the strongest and most powerful brands as a retail powerhouse that could come close to challenging Tesco, in southern England at least, while at the same time creating tremendous economies of scale.

The two brands, however, do not sit comfortably together. A deal would mean M&S giving up its premium positioning in food in favour of a mass-market proposition. In fashion, while it has been aggressively reducing entry price points, it is still a long way from being the value offer that Sainsbury's and the other supermarkets provide.

The result would be that in the remote scenario that M&S did go ahead and buy Sainsbury's, it would find its margins diluted towards Sainsbury's tight levels - particularly because the business would become all about the brutal exercise of taking on Tesco.

Stuart Rose is a consummate retailer, but so was Sir Ken Morrison and we all know what happened when he bought Safeway. It's right that, given Sainsbury's is now in play, the M&S board is discussing a move for the business. But it would be wrong if they took it forward.