Banks poised to raise mortgage rates independently of the Reserve Bank. Is it now a question of how much and when?

Australia's big banks could take yesterday's Reserve Bank decision on interest rates as a green light to raise the cost of borrowing, despite Treasurer Wayne Swan's "jawboning", an economist has warned.

The RBA left the official cash rate on hold yesterday, saying the decision was based on observations of growth in China and the United States, decreasing concerns over Europe, and strength in the local economy.

Economist Stephen Koukoulas has told AM the banks might see now as a good time to claw back some of the costs they incur from sourcing funds on global markets.

Listen to the interview here.