Greens MP Adam Bandt has criticised the ANZ Bank for hiking its loan rates by 6 basis points in defiance of the Reserve Bank decision to keep interest rates on hold.

Mr Bandt said the big banks were breaking their social contract with the Australian people.

Mr Bandt said the decision was also serious challenge to monetary policy at a time when the economy is facing serious challenges from the global situation.

He said the government should now get behind a Greens bill to require banks to provide a tracker mortgage with rates that would rise and fall with the cash rate.

"The banks are breaking their social contract with the Australian people," Mr Bandt said.

"The time for tough talking from the Treasurer and the Opposition is at an end. Now it's time for action and the government should support The Greens' bill to rein in excessive profiteering."

"ANZ's decision is also a challenge to monetary policy at a time when the global economy may mean action is needed."

"Wayne Swan should not let ANZ get away with it."

The Green's Banking and Consumer Credit Protection Amendment (Mobility and Flexibility) Bill, currently before parliament, would force banks to provide loan products that track changes to the Reserve Bank cash rate and also make it easier for consumers to switch mortgages by changes to mortgage lenders insurance.