Thousands marched through the streets of Edinburgh on Saturday. The crowd, which straggled its way from the Royal Mile to the great stone columns on Calton Hill, were marking a year until the referendum for Scottish independence.

Amongst them were a group of artists, writers, filmmakers and photographers, all sporting the same black and white T-shirts. One man held aloft a cardboard placard: “Aye, have a dream.” Another, hand painted in green, girlish letters, read: “Vote as if you live in the early days of a better nation,” a play on the slogan made popular by the writer Alasdair Gray.

The marchers represented a growing grass roots movement among the arts community in Scotland, who are lending their skills to the nationalist cause. They are young. They are creative. They are witty and sometimes brash. They call themselves ‘the National Collective’.

The National Collective is a non-party political body – although, like the rest of the country, it tends towards the left – which seeks out new ways to inspire an undecided Scottish electorate to vote ‘Yes’ come next September.

The collective made headlines earlier this year when it published an article criticising Ian Taylor, the unionist campaign’s biggest donor and chief executive of the oil company Vitol, noting that – amongst other complaints – his firm had been found guilty of grand larceny in the US in 2007 after paying $13m in kickbacks to Iraqi officials under Saddam Hussein for oil contracts.

(Threats from Taylor’s solicitor’s prompted the collective’s website to go offline shortly afterwards – offering only a page of static and Mogwai’s Music for a Forgotten Future. The article has since been republished.)

Since then support for their campaign has ballooned. Last month its website received 80,000 hits, and there are now local chapters in all the major Scottish cities – Edinburgh, Glasgow, Dundee, Stirling, Inverness and Aberdeen.

I met two of the core members – Mairi McFadyen, an academic at Edinburgh University, and Ròs Hunter, a student at Glasgow – over a coffee at the Fruitmarket Gallery, where the trains of Waverley Station below make themselves known in a rumbling through the foundations.

Mairi is a founding member of Trad Yes, a group of folk musicians keen to express their support for independence. She said: "We don't want our musicians to make their gig a political event. But we ask them to have a banner on stage, or mention the campaign during the performance, to make their support known."

The National Collective promotes their contributors in a number of different ways. New writing and images are published on the main website; musicians, spoken word and short films showcased on a dedicated YouTube channel.

Ròs explained: “Anyone who wants to suggest a new project can fill in an online document outlining their proposal, telling us what they'd need us to provide or what resources they can offer. They might want to borrow a camera, or need some volunteers to help at an event, or they might just need coloured paper and pens."

Her 'wish tree' project asks supporters to write what they would like to see from an independent Scotland onto coloured paper tags, which are then tied to a branch or string. Wishes range from deadly serious (“We decide which wars we fight”) to flippant (“More sunshine and fewer midgies!”), but together they offer a broad brush impression of a great hope for the future.

Indeed, the pair are almost giddy with the possibilities, recounting the aspirations and travails of the campaign with a rare earnestness, both in vigorous agreement that the Collective is one outlet through which young Scots are growing in “cultural confidence”.

Such enthusiasm is infectious. The National Collective has attracted warm words from a number of high profile Scots, including the national poet Liz Lochhead, the author Alasdair Gray and the comedian Elaine C Smith.

The playwright Alan Bissett, whose (ironic) poem Vote Britain (“Vote with your heart. Vote Empire.”) has become a rallying cry amongst the nationalist movement, joined the collective as a 'creative ambassador'.

He said: “Artists are by their nature suspicious of party politics, since this almost invariably means toeing some kind of line - which is the death of the imagination. At the same time, however, we understand the value of collaborating on a project larger than ourselves as individuals, since that’s how musicians, film-makers and playwrights work.

"The National Collective gives us the chance to explore the independence issue flexibly and with a creative spirit: no conversation is off-limits and nothing feels coercive. We want to be anarchic, outspoken and free."

Their support reflects how the wider creative community in Scotland have rallied around the Yes campaign. As has been remarked upon in the Scottish press, there are few in the arts willing to admit to unionist sympathies, despite a flood of names declaring in the opposite direction including Annie Lennox, Jack Vettriano and Frankie Boyle (and many more, which have been compiled in a list on the National Collective’s website).

It’s a surprising trend, given that the level of support for independence amongst the general population hovers around 30%.

A number of factors play a part in this surge of support from the creative community, not least because the Scottish Government has traditionally placed a lot of emphasis in funding for the arts – particularly when seen in comparison to the Coalition government at Westminster. The national arts agency Arts Council England saw its budget slashed by almost a third in 2010 and by a further 5% earlier this year; its equivalent, Creative Scotland, on the other hand, has seen its budget cut by a mere 2%.

The First Minister Alex Salmond too has personally shown his admiration of a number of Scottish writers by quoting from their work in his speeches. Last year he read The Nonsense Ends by little-known Edinburgh poet George Robinson at the SNP party conference (“Not I and more are yet content / With just a devolved parliament.”), the year before invoking Robert Burns’ A Red, Red Rose when he promised that “the rocks will melt with the sun before I allow tuition fees to be imposed on Scottish students.”

Thus Salmond grasps that the poet may be better placed to inspire than the politician, even going so far as to declare that he would be asking “one of Scotland’s great literary talents” to help write the Scottish Government’s upcoming white paper on independence, due to be published in November. (The novelist William McIlvanney has been tipped for the role, but there has been no confirmation.)

There too is the inherent romanticism of an independence movement: the struggle for freedom makes a grand narrative, with which the more pressing fight – the struggle against apathy – can be fought.

Campaigning to maintain the status quo, which is what the unionist movement Better Together is tasked with, is a less inspiring task. But then, the No campaign doesn’t need to inspire; creating uncertainty will almost certainly be enough to lure the canny Scots to remain within the safety of the Union.

Better Together, led by the former Chancellor of the Exchequer Alistair Darling, has faced claims of fear-mongering, after initial arguments centred around the risks of independence (the oil money running out, banks sinking the economy, the EU barring re-entry), in a bid to present this scrappy little country as incapable of looking after itself. This approach did not sit well with the public, but as Darling himself remarked, “the onus is on those who want to break up the union to explain why going-it-alone would be better for Scotland.”

Police estimated the crowd at the rally on Saturday to number in the region of 8,300. Its organisers disagreed, claiming that between 20,000 and 30,000 turned up. Either way, it was a good show in a city with a population of less than 500,000.

Nevertheless, to win the referendum, the Yes campaign needs the support of many hundreds of thousands more. It’s a big ask, but they have some of the country’s most inspiring voices on their side. Is it possible? Certainly. Is it likely? Well, who knows.

The Dundee-born novelist AL Kennedy said: “Arts workers might feel that being in a more progressive, autodidactic atmosphere would be good in general and good for them personally. They may feel an independent, left leaning Scotland would be that place. Some people always feel they might be a bigger fish if the pond was smaller, some want to get creative with a whole new start for their country.

“It will be an interesting time, the next few months... but the cultural ground work and confidence and architecture are all there. That's not in doubt. This is a vote about whether Scotland's politicians measure up or not.”