LONDON, April 18 (Reuters) - UK stocks fell sharply on Tuesday, with the bluechip FTSE 100 poised for its sharpest one-day drop since the aftermath of last year's Brexit referendum, after Prime Minister Theresa May called for an early election.
The strength in sterling, which rose to levels last seen in December 2016, dented appetite for shares of UK-listed exporters such as mining and oil stocks which were already on the backfoot even before May's surprise announcement.
The FTSE 100's slide on the day left it less than 0.5 percent away from dipping back into the red for the year.
British Prime Minister Theresa May called for an early election on June 8, saying she needed to strengthen her hand in divorce talks with the European Union by shoring up support for her Brexit plan.
The UK midcaps index, which comprises more domestically focused firms, fell 1.1 percent, retreating from last week's record high. European shares slipped 1 percent.
BHP Billiton, down nearly 5 percent, was the worst performer on the FTSE 100 followed by peers Anglo American and Glencore. Barclays shares fell 3 percent. (Reporting by Helen Reid and Kit Rees, Editing by Vikram Subhedar)