Pound soars but FTSE falls after Theresa May's Brexit speech

Sterling makes biggest one-day gain against dollar since 1998, but analysts say rally likely to be temporary

The pound has clocked up its biggest one-day gain against the dollar since 1998 as traders seized on Theresa May's pledge that parliament would vote on any Brexit deal and welcomed some clarity on the government's plans for leaving the EU.

The FTSE 100 headed in the other direction, recording its biggest daily fall since the immediate aftermath of the Brexit vote in June. The share index has been boosted for several months by the fall in the pound, which helps exporters and those companies with overseas earnings, and some of that effect was unwound on Tuesday as the pound jumped almost 3%.

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