During a 24-hour visit to Shetland last week, Deputy First Minister Nicola Sturgeon opened a Yes Shetland shop in Lerwick that pro-independence campaigners have raised almost £1,800 through crowd funding to rent and equip for the duration of the referendum campaign.

When it opened, Cindy's Hair Stylist, two doors away, responded by putting up two Union flags in the window.

"Don't quote me," said the manageress, before declaring her staunch stand for a No vote on September 18.

Two middle-aged women having their hair done nodded in agreement, the only member of staff adding: "Hundreds of people, men and women, come here and maybe two have said they will vote Yes."

No one has ever doubted Shetland is a stronghold for the Union. It has been a Liberal or Liberal Democrat stronghold since 1950. It decisively rejected devolution in the 1979 referendum, with only 27% of the vote being in favour.

But in 1997 the comparable figure was 62.4% and some believe the winds of change have been continuing to blow over the past few months.

Yes campaigner Brian Nugent said when they started out they were given a hard time. "It was very difficult, very few people were speaking to us, those who did were generally No and telling us off. Latterly, it has got much better."

Turnouts at public meetings, including local LibDems' MSP Tavish Scott's marathon Ferry To The Referendum tour of every island community, have barely reached double figures, with both sides generally preaching to the converted.

However, a referendum debate with Scottish Secretary Alistair Carmichael in March was attended by 150 people with the before and after vote showing a marked swing to Yes.

And last week's BBC Radio Shetland debate at Shetland Museum and Archives packed the 120-seat auditorium. An appearance immediately afterwards by Ms Sturgeon swelled the numbers even more.

One thing everyone agrees on is the referendum has revived interest in politics in Shetland.

Local electoral registration officer Ian Leslie has been astonished by the last-minute rush of applications for postal and proxy votes. "There is an interest in the democratic process I have never seen before, and that can only be a good thing," he said.

Lerwick Community Council chairman Jim Anderson said he had been "heartened" at the "good-natured" discussion that seems to be going on everywhere.

"It is not a case of 'I am right and you are wrong', folk are pro-actively engaging in the almost forgotten art of conversation."

Fish trader Karl Simpson has engaged in this conversation with an energy that has surprised even himself. "Normally, I would not be so outspoken, but if it all went wrong in the future I would be asking myself, 'what did I do?'."

A confirmed No voter, Mr Simpson said he had been taken aback by the number of people he knows that are voting the other way. "I think Shetland will vote No. A few years ago it would have been 80:20, now it may be 70:30 or even 65:35," he reckoned.

He is also surprised at the growing influence of Scottish culture in the isles. "When I was a bairn you would go to any length not to identify yourself as Scottish. Twenty years ago you would never see a kilt at a wedding, now every groom has a kilt."

Mr Simpson would like to see Shetland follow the example of its Faroese neighbours and become a Crown dependency, like the Channel Isles or Isle Of Man.

But he says Shetlanders are too comfortable to follow that route. "There is no groundswell of feeling amongst Shetland folk in that way. It would take a hell of a lot of things to go wrong to change that - your average Shetlander is too well off."

A petition from a nebulous group calling for a second referendum for the Scottish islands in the event of a Yes vote attracted only about 1,300 signatures worldwide, and was rejected by the Scottish Government.

However, the Our Islands, Our Future campaign by the three island councils has been widely regarded as a success, cleverly playing the two Governments in Westminster and Holyrood off against each other to gain post-referendum promises of greater powers.

Mr Simpson and others were disappointed the Our Islands, Our Future campaign did not play "the oil card" at a time when Shetland is awash with thousands of construction workers building the gas plant that will open up the substantial fields west of Shetland.

But Lerwick councillor Jonathan Wills is full of praise for the three council leaders, particularly Shetland's Gary Robinson. "They took advantage of an opportunity and have already got something out of it," he said.

Mr Wills, who was the first student rector of Edinburgh University and is a friend of former Prime Minister Gordon Brown, is a confirmed Yes man. He, too, is noticing the swing towards independence, especially amongst fishermen who want Scotland to have its own seat at the negotiating table.

"The discards ban will be a disaster for the white fish industry. Westminster has done nothing about it, but the Scottish Government and Shetland Islands Council have tried to get Europe to understand the damage this will cause."

Veteran SNP campaigner Danus Skene is also more upbeat. "I have never thought we would be able to win Shetland, but I think we can make it a lot closer than a lot of people expect," he said.

Meanwhile, marine engineering consultant and former SIC vice-convener Jim Smith has already cast his No vote by post, though not with any great enthusiasm. His initial concerns about currency and pensions have been assuaged, but there remain "so many imponderables".

"I am taking the safe way out," he said. "We know what we have got, I am not entirely happy about it, but I don't know what we are getting (with independence) and I presume I won't be happy with that either.

"We're either going to be ruled by a bunch of Hooray Henrys in Westminster or a bunch of Red Jimmys in Glasgow."