The Scottish isles are emerging as the latest battleground in the fight between supermarkets, as the number of opportunities in towns on the UK mainland dwindles.

Arran, off the west coast of Scotland, has a population of under 5,000 and has never been able to tempt a major supermarket to its shores before, but that may be about to change.

With three stores, The Co-operative Group currently has a monopoly on Arran, which is one hour by ferry from the mainland.

But Asda is working on a plan that would enable inhabitants to shop online for groceries and get them delivered to their doors from a store based on the Scottish mainland.

Arran shoppers currently have to spend £10.50 on the return ferry trip if they want to shop at Asda .

Only “people with nothing better to do” bothered, said Alison Prince, editor of The Arran Voice weekly newspaper.

Under the online scheme, the goods would be delivered from its store in Ardrossan, the town where the ferry port to Arran is based.

But islanders had mixed views about the plan, she admitted. “We did a vox pop and the villages with the most disadvantaged people welcomed it . But the fear is that it may rebound on small local shops and take custom away from the Co-op, which a lot of people support because of its Fairtrade and ethical policies.”

An Asda spokesman said: “We are looking into this but it is not likely to be this year. It would be a case of operating from our Ardrossan store and sticking a van on the ferry. We are always looking to supply where there is a demand.”

Arran is the latest Scottish isle to attract the attention of the multiples. Tesco recently bought a store on Shetland, the first of the big four to establish a presence on the island; and The Highland Council has this week approved plans for a Tesco and a Lidl on Skye.