A litre of petrol might become more than 60c more expensive and diesel about 40c, statistics released by the Central Energy Fund suggest.

This would be on top of the increases of 22c a litre for petrol and 15c for diesel of Wednesday last week.

The fund's numbers show an average under-recovery on petrol of about 65c a litre for the first 10 days of the month, usually a forerunner of a price increase.

On diesel. the under-recovery was 40c a litre.

But, with the oil price still on the rise, the increase could be even bigger.

Brent crude oil was trading at a 12-week high of around $112 a barrel yesterday.

Sanctions against Iran and continuing tensions in the Middle East that have put upward pressure on oil prices for the past few months are not likely to be eased any time soon.

Next month's fuel-price increase would be on top of spiking food prices and more expensive electricity.

The Bureau for Economic Research and First National Bank consumer confidence index showed last month that consumers are at their most pessimistic since early 2008.

"Consumers' rating of the prospects for the national economy, the outlook for their own finances and the appropriateness of the present time to buy durable goods all deteriorated notably," said the bureau.

The business confidence index was at its lowest in 12 years.