Sterling jumped 0.8 per cent to its highest level in three weeks on Tuesday, after data showed British inflation last month shot past the Bank of England's 2 per cent target for the first time since the end of 2013.
Consumer prices leapt by a stronger-than-expected 2.3 per cent in annual terms, beating expectations of a 2.1 per cent rise, and up sharply from 1.8 per cent in January, the Office for National Statistics said.
The pound, which had already been trading up 0.4 per cent at $1.2416 before the data, rose to a high of $1.2462 - its highest since February 28 - after the data.
It also hit a day's high of 86.62 pence per euro.
The internationally focused FTSE index turned negative as sterling gained, down 0.2 per cent after the data.
British government futures fell around 30 ticks to 125.60, down 67 ticks on the day.