The FTSE 100 has extended falls and is now down 0.90% at 7,442.89.
Online grocery delivery company Ocado is now leading the blue chip fallers, down 5.4% at 865p. It is closely followed by luxury fashion house Burberry, down 5% at £19.25.
Barclays is the biggest riser, up 1.4% at 174.9p.
Clothes retailer Ted Baker is leading the FTSE 250's fallers, down 9.1% at £20.97 following a fall in interim pre-tax profits.
Mining group Ferrexpo is the top riser, up 8.35% at 227.1p.
The FTSE 250 is down 0.80% at 20,137.70.