The FTSE 100 fell on Friday and was set to record its worst week since October, as stalled vaccine rollouts and lockdowns to curb the spread of contagious new coronavirus strains kept investors from jumping into riskier assets.
The blue-chip FTSE 100 index dropped 0.9%, with energy and mining stocks being top drags for the week, while the mid-cap index fell 0.7%.
Drugmaker AstraZeneca fell 3.6% for the week and was one of the top drags on the blue-chip index on Friday, as a tussle with the European Union on vaccine rollouts continued to weigh on the stock.
"Clearly, there have been a few new concerns with the relationship with the European Union on the vaccine in recent days and that hurt the markets. It has also led people to take some profits," said Chris Bailey, a strategist at Raymond James.
The European Union's contract with AstraZeneca for its Covid-19 vaccine contains binding orders, EU Commision Head Ursula von der Leyen said, demanding a plausible explanation from the drugmaker for delivery hold-ups.
The benchmark indices were also set to fall for the month, with the mid-cap index on track to record its worst monthly loss since September.
The export-heavy FTSE 100 recorded consistent monthly gains since November, but it has recently lost steam and currently trades at a near six-week low led by worries of elongated economic pain due to a surge in virus cases and lockdowns.
Britain will ban direct passenger flights from the United Arab Emirates from Friday, shutting down the world's busiest international airline route from Dubai to London, to curb the spread of a new variant of coronavirus.
Online fashion retailer Boohoo gained 0.7% after it confirmed it was in exclusive talks with the administrators of Philip Green's collapsed Arcadia group over the purchase of the Dorothy Perkins, Wallis and Burton brands.