LONDON (Reuters) - Britain's current account deficit widened by more than expected in the first three months of 2020, official data showed on Tuesday.The Office for National Statistics said the balance of payments deficit - a long-standing concern for investors because it leaves Britain reliant on foreign inflows of cash - grew to 21.1 billion pounds ($25.9 billion) in the first quarter, compared with a median forecast of 15.4 billion pounds in a Reuters poll of economists.($1 = 0.8147 pounds)