Neither the dollar nor the euro had a great week. Both lost a cent and a quarter to sterling and the dollar was down by two yen against the safe-haven Japanese currency. The dollar's problem was a gnawing suspicion that Donald Trump might not be able to deliver the stimulative programmes that enthused buyers at the end of last year. He is currently facing his first test in Congress, with uncertainty about whether his healthcare bill will pass the House of Representatives. Were it to be defeated it would cast doubt on Mr Trump's other legislative ambitions.

Sterling would have had a better week had it not stumbled when the prime minister named the day for triggering Article 50. It recovered after UK inflation came in well above forecast at 2.3%. No early interest rate increase is expected but it is likely that opinion is leaning in that direction in the Monetary Policy Committee.