Pound slumps to 31-year low versus dollar

The pound slumped to a 31-year low against the dollar Tuesday on concerns over the timing of Britain's planned exit from the European Union, according to traders.

Britain's currency also struck a fresh three-year low point against the euro, while the drops helped pushed London's benchmark FTSE 100 stocks index up to a 16-month high beyond 7,000 points at the open.