Madrid was then forced to pay 50pc more than in March to drum up interest in a €2.5bn (£2bn) bond. By then end of the day, borrowing costs for benchmark 10-year sovereign debt in Spain rose 2 basis points to 6.21pc, while gilts and German bunds dropped to fresh lows of 1.834pc and 1.41pc respectively. Britain’s debt management office was swamped with record demand for a 'safe haven’ £1.5bn gilt auction.