Motorists 'feeling the pinch' with high fuel prices in rural areas
A fuel discount that applies to the Scottish islands and the Isles of Scilly could be extended to remote and rural parts of the UK mainland.
The scheme, which was introduced last year, gives motorists a maximum 5p per litre reduction in duty.
The UK government is now looking at petrol and diesel prices in 36 areas in England, Wales, Scotland and Northern Ireland.
In Wales businesses in Gwynedd, Isle of Anglesey, Monmouthshire, and Powys have been asked for information.
Motorists at Dolydd near Caernarfon, Gwynedd, told the BBC's Aled Hughes that they were feeling the pinch.