Australia's major banks have not been uniform in their response to the Reserve Bank of Australia bringing interest rates to a new record low of 2 per cent on Tuesday.

The Commonwealth Bank announced it will not pass on in full the latest cut to the official interest rate. Australia's biggest lender said it would wait until next Wednesday to cut its standard mortgage rate by 0.2 percentage points to 5.45 per cent, the lowest CBA rate in history.

Westpac also held back from passing on the full rate cut, lowering its variable mortgage rate by 22 basis points to 5.48 per cent.

ANZ Bank announced it would pass on the cut in full, effective on Friday, taking its standard variable mortgage rate to 5.38 per cent.

On Wednesday, National Australia Bank said it would reduce its standard variable rate by 0.20 per cent per annum to 5.43 per cent, effective from May 13, the lowest it’s been since 1978.

Treasurer Joe Hockey said he would be angry if banks didn't pass on the rate cut in full, stating that "when the Reserve Bank acts, we expect the banks to also act in full as well."

On Wednesday, CBA shares plunged 5.9 per cent to $82.98, wiping $8 billion from its market capitalisation. Westpac Banking Corp dropped 3.7 per cent to $33.99, while National Australia Bank and ANZ Bank fell 2.7 per cent.