The return of Home Retail Group to the FTSE 100 after an absence of six months proved to be a significant disappointment. Shares in the parent company of Argos and Homebase dropped 13 per cent to 204p – the worst performance by a blue-chip company – as investors booked profits and worried about the impact of promotional activity on margins.

Home Retail had enjoyed a good run since the start of the month, helped by traders buying stock in anticipation of its promotion. But sellers gained the upper hand as the company launched its latest sales, offering 50 per cent off thousands of items at both of its chains.