Although uncertainty about Brexit has hurt the pound, the currency has been bolstered in October as the chances of a no-deal exit have been all but eliminated. It was against that backdrop the pound retraced its initial losses after Johnson announced his third attempt to force a snap poll. The pound was last down 0.575% to $1.285. It is currently up nearly 5% this month.
After surging to a 5-1/2 month high on Monday, the pound has come back under pressure after British lawmakers blocked Johnson's plan to push through a withdrawal agreement and get the UK out of the EU on October 31.
The Brexit end game is more uncertain than traders thought last week, setting up the pound for another rocky period. Against the euro it dropped 0.37% to 86.47 pence per euro.
In the UK, data this week showed the government was likely to miss a goal of keeping borrowing below the threshold of 2% of GDP, reflecting weakening public finances even before Brexit. The Brexit optimism had led money markets to slash the chances of interest rate cuts next year but those estimates are creeping higher again, with a cut now 90% priced for December 2020, up from 60% a week ago.