Latest Australian Institute of Petroleum figures show that the state's petrol prices are more than 10c higher than the national average  and rival some of the most remote towns in Australia.

Those living at Wynyard  and New Norfolk are forking out the most for fuel in the state, paying 20c more than Melbourne motorists  and 6c  more than those living in Kalgoorlie in Western Australia.

The figures come as the federal government is poised to include an increased fuel excise of about 3c a litre in tomorrow's federal budget.

Royal Automobile Club of Tasmania chief executive Harvey Lennon said the figures showed evidence of ``market failure''.

``I just don't think you can justify the difference in price based on freight alone,'' Mr Lennon said.

``It doesn't seem equitable.'' 

Mr Lennon said he would push to speak with federal ministers to ``reinforce concerns on excise tax''.

``We'd like to make the federal government  appreciate that there's already inequity and that further increasing the price exacerbates the situation,'' he said.

Mr Lennon said the influence of the two major supermarket chains had been significant in generating increased prices.

Bass Liberal MHR Andrew Nikolic said Tasmania missed out on the discount price cycle experienced on the mainland.

``You can't force petrol companies to compete,'' Mr Nikolic said.

``I actually think we're being taken for granted and I think we're being treated as second-class citizens.''

Mr Nikolic said transporting petrol to the state added a cost, but it could only account for about 5c a litre.

``Why doesn't Tasmania deserve the same discount price cycle as the mainland?'' he  asked.

Mr Lennon said a federal petrol watchdog had been a toothless tiger and was unsuccessful in keeping down prices.

``We're calling on the state government to advocate on behalf of Tasmanian motorists,'' he  said.

``People are doing it tough, and petrol is just another thing that makes it harder for Tasmanians.''

A state government representative said the government was listening to the concerns of motorists and lobby groups, including the RACT.