The blue-chip FTSE 100 was down 0.4% by 0719 GMT, having fallen to its lowest level in over 18 months earlier. The midcap FTSE 250 dropped 0.2% to hold near May 2020 lows.

Housebuilder Taylor Wimpey dropped 4.8% as it traded ex-dividend. The broader homebuilder index fell 1.3% to touch its lowest level in almost a decade.

A survey showed British house prices rose last month at their slowest pace since early in the coronavirus crisis and they look on course to fall as a surge in mortgage costs adds to uncertainty about the economy for home-buyers.

The pound slipped in choppy trading, after finding a brief respite on Wednesday, amid concerns about the bond market turmoil that has pushed the Bank of England to intervene.

GSK edged higher after late-stage data showed the drugmaker's respiratory syncytial virus (RSV) vaccine was 82.6% effective in a study involving older adults.

(Reporting by Sruthi Shankar in Bengaluru; Editing by Savio D'Souza)