The pound slumped more than 1pc against the dollar Friday after official data showed tumbling retail sales as Britons grapple with a cost-of-living crisis. In London morning deals, sterling sank to $1.2887 — its lowest level since October 2020, also as Prime Minister Boris Johnson comes under renewed political pressure. London’s benchmark FTSE 100 index was down 0.5pc, as shares in retailers fell sharply on the data. News that UK retail sales had plunged by 1.4pc in March could put the brakes on the Bank of England’s policy of hiking interest rates to curb soaring inflation. Britain’s currency has strengthened recently after the BoE hiked interest rates three times in a row.