Hockey given paper on card rates in March

Treasurer Joe Hockey was given an internal discussion paper by Treasury on credit card interest rates back in March, a Senate estimates hearing has been told.

A general manager in Treasury's markets group Meghan Quinn told the hearing on Tuesday that the internal paper was handed to Mr Hockey on March 25.

But Liberal senator Scott Ryan, representing the treasurer, took on notice whether it would be made publicly available.

Senators are trying to pursue an inquiry into credit card rates after being told on Monday that the gap between the official cash rate, now at a record low of two per cent, and credit card rates are at a record high.