Over the past few days petrol prices have gone up by as much as 20 cents a litre in some parts of the country, with $1.40 a litre seen as a new benchmark in January.
The Australian Institute of Petroleum figures show the national average price of unleaded rose 2.2 cents over the week to Sunday, hitting 128.3 cents per litre.
But the national average masks extreme regional variations.
At $1.22 per litre, Melbourne's prices were relatively steady and only barely above the terminal gate wholesale price that service stations are paying.
However, residents in Sydney and Adelaide were being stung with average prices above $1.40 a litre.