The most amazing thing about Malcolm Turnbull's bank bashing charade this week was that he managed not to blush.

The Prime Minister on Wednesday went through the motions of chastising the big banks and calling for them to match the Reserve Bank's 25 point reduction in the cash rate with a straight face, perhaps relying on the public having the attention span of gnats.

Or maybe Turnbull suspected he had greater embarrassment coming with the declaration of the Senate results for NSW, and therefore didn't care about the token interest rate rave - which he followed up on Thursday with news the big four banks' chiefs will have to appear before Parliament's economics committee at least once a year.

It was of course only a few short years ago that the Coalition was the opposition and accused the then-government of all sorts of inept powerlessness when the banks reduced rates by less than the cash rate reduction. Something about Wayne Swan and a wet lettuce comes to mind.