Just Eat Takeaway and Ocado were among the few top flight stocks doing well as investors eyed a renewed surge in business from families stuck with Tier 4 restrictions.
The FTSE 250 index also showed the strain of Brexit stalemate, diving 409.25 points to 19,707.04. Fallers included Countryside Properties, despite an agreement with Sigma Capital to deliver 5,000 new private rental sector homes in England. Shares fell 16.2p to 423.8p.
On AIM, diagnostics firm Novacyt resumed its recent strong run, rising 76p to 902p after it said its testing kits can detect the latest variant of Covid-19.