Petrol pumps and other fuel retailers in remote areas in Britain have been asked to let the Government know how much they charge for petrol and diesel so ministers can seek the necessary permission from the European Commission to extend the discount scheme.
Currently, islanders within the Inner and Outer Hebrides, the Northern Isles, islands on the Clyde coast and the Isles of Scilly get a 5p discount on petrol and diesel because the costs of transporting fuel there means prices are much higher.
Now nine Scottish mainland areas are among the 35 UK districts where data is being sought from 1500 retailers: Aberdeenshire, Angus, Argyll and Bute, Dumfries and Galloway, Highland, Moray, Perth and Kinross, the Borders, and South Ayrshire.
Mr Alexander said it will not be easy to get the required approval from the Commission and other European Union member states but the Government would strive to make it a reality for areas that qualified for the discount.
He said: "The island fuel rebate provides much needed help to keep down fuel prices in areas where costs of transporting fuel mean prices are much higher. I know that there are other remote rural areas of the UK with similarly high fuel costs.
"So we are today starting to gather further evidence that will form part of an application to the Commission to extend the island fuel duty discount scheme to very remote rural areas. We will need to prove that there are areas which are similar to the islands in terms of pump prices and distribution costs so I would urge local areas that may qualify to provide the information we need to make the case as robust as possible.
"As a Highlander, I know that for people who live in rural areas driving is not a choice, but a necessity. So while it won't be easy to get this agreed with the Commission, I want to do everything I can to make this happen."
Campaign group FairFuelUK said that even if the consultation is successful it would only help a small number of people and businesses and called for a fuel duty cut across the whole country.
Quentin Willson, FairFuelUK spokesman said: "I welcome the Treasury's acknowledgement that the UK needs a duty cut, but we need it across the country, not just for remote communities. Everybody is hurting not just the few."
The Treasury said it is most interested in identifying areas where prices were consistently similar to those on the islands that currently fall under the scheme.
Places where prices were consistently lower than those on the islands currently covered are "extremely unlikely" to be included in any extension of the discount scheme.
:: Fuel retailers in the following areas are being asked to send pump price data to the Government:
Aberdeenshire, Angus, Antrim, Argyll and Bute, Armagh, Ballymena, Ballymoney, Banbridge, Coleraine, Cookstown, Cornwall, Cumbria, Devon, Down, Dumfries and Galloway, Dungannon, Fermanagh, Gwynedd, Herefordshire, Highland, Isle of Anglesey, Larne, Limavady, Magherafelt, Monmouthshire, Moray, Moyle, Newry and Mourne, North Yorkshire, Northumberland, Omagh, Perth and Kinross, Powys, Scottish Borders, South Ayrshire, and Strabane.