As the Takeover Panel slapped a put up or shut up order on the private equity consortium circling Sainsbury's this week, an interesting new sub-plot has emerged, with legendary property tycoon and private equity investor Robert Tchenguiz taking a 3% stake in the supermarket -

despite the record 539p share price.

The panel, contacted by Sainsbury's last Friday, has given the CVC, Kohlberg Kravis Roberts, Blackstone and Texas Pacific Group consortium until 13 April to put an offer on the table.

Tchenguiz, who spent £280m on the 3% stake, was also involved in Violet Acquisitions, the consortium that bought Somerfield in 2005. His plans are not known, but his choice of bankers is thought to rule out any further involvement by another Citibank client, Marks & Spencer. CEO Stuart Rose mysteriously pulled out of a bid within 24 hours of promising shareholders to "watch this space".