British inflation has hit its highest level in almost six years, official data showed Tuesday, forcing Bank of England governor Mark Carney to explain the rise in an exceptional letter. 

The Consumer Price Index climbed to 3.1 percent on a 12-month basis in November compared to 3.0 percent in October, the Office for National Statistics (ONS) said in a statement. 

Analysts' consensus forecast had been for no change to the CPI reading.

Carney must send a letter to British finance minister Philip Hammond, explaining why inflation overshot the Bank of England's 2.0-percent target rate by more than one percentage point.