North West counties in particular are at risk of falling into a two-tier fuel economy.
That's the view of Independent Sligo Leitrim TD, Marian Harkin, after fuel excise hikes came into effect on Monday.
The cost of petrol has jumped up by 4 cent per liter, while diesel increased by 3 cent and marked gas by 1.5 cent.
It is the latest step by Government to restore excise rates after a temporary cut was introduced two years ago, with another rise in excise duties scheduled for August.
Deputy Harkin feels that this will have a significant impact on counties close to the border, as fuel prices are cheaper in Northern Irish counties: