Mr Hartsuyker cited figures from fuel price monitors Motormouth showing that LPG could be bought at a service station in Petersham, Sydney, for 39.9 cents per litre and at a significant number of other retailers for less than 43c/l.

But on the North Coast of NSW, many retailers were charging 69.9c/l, up to 30c/l more.

"Regional motorists quite rightly ask how this price difference can be justified," Mr Hartsuyker said.

"Of course, the rural and urban markets are different but they're not that different and motorists understandably think they're being taken for a ride."

His criticism follows those of his party leader Warren Truss, who yesterday called on the Australian Competition and Consumer Commission to investigate the price disparity between unleaded and diesel.

Mr Hartsuyker has also written to the ACCC Petrol Commissioner asking for an explanation for this "price discrepancy".

"What we need from the ACCC is either decisive action to end the price disparity on LPG and diesel or a convincing explanation why regional motorists are paying far more than motorists in the cities," Mr Hartsuyker said.