Motorists and businesses will be paying higher prices at the bowser as a reduction to the fuel tax comes to an end.
The federal government temporarily halved the fuel excise in April, slashing 26 cents off a litre, in response to soaring global oil prices caused by the war against Iran.
The $2.5 billion measure is planned to run out at the end of June.
Australia's peak motoring body is warning, based on current prices, the average for unleaded petrol in Sydney in July will be 40 cents higher than before the start of the war against Iran, at $1.99 per litre.
Diesel would be 65 cents higher at 2.37 cents per litre.
Transport Minister Catherine King indicated it would not be extended further even as conflict continues in the Middle East.
