“Scottish independence isn’t about borders or flags, it’s about people’s lives and change.” – Scottish independence campaigner Cat Boyd presents the case for Yes at a meeting in the House of Commons.

There is today a political movement in Scotland that is quite beyond anything containable by or even comprehensible through the terms of conventional parliamentary, tick-some-scoundrel’s-name-every-four-years politics. Many of us south of the Scottish border have had our political senses so numbed for so long by broken promises of change that it’s taken a long time for people to wake up to this fact – but wake up we must.

The question posed in next month’s referendum, yes or no to independence for Scotland, was intended by British prime minister David Cameron to make the alternative to the status quo look so radical that the forces of conservatism would win out – but it hasn’t gone according to plan. The chance to vote on Scotland’s future has in fact brought about a popular mobilisation for radical social change unlike anything we have seen in these islands for a generation.

The conditions for this mobilisation were, it’s true, put in place by theScottish National Party (SNP) and its skilful, long-honed, management of conventional electoral politics and its associated media. There would be no referendum if Alex Salmond’s SNP had not become the party of government in the Scottish parliament at Holyrood and used what bargaining power he had to extract the commitment to a referendum from David Cameron. But as Cat Boyd insists above, the movement for independence that the referendum has unleashed is not about Alex Salmond, the SNP or the normal accoutrements of nationalism.

Cat was speaking at a meeting in the UK parliament in Westminster, organised by Red Pepper and openDemocracy to bring the case for independence to the ‘belly of the beast’. Neal Ascherson told that meeting: “Gordon Brown has said that this is a campaign for or against the SNP, but he is completely wrong. It is a huge mass mobilization.”

The referendum has become an invitation to say no to a superpower whose wars, most recently against Iraq, the Scottish people found abhorrent and yet were forced to join; a chance to say no to decades of social injustice and sacrifice at the altar of the global market by Conservative and Labour governments at Westminster, for which Scottish voters did not vote. It is, finally, a chance to refuse a democracy without substance in which MPs working 300 miles away and more are too distant to be accountable or subject to popular pressure.

Most importantly, Scottish people have grasped the choice that they have to make directly – unmediated by the political class – as an opportunity to imagine the kind of society that they, the Scottish people, could build with the democratic possibilities of independence. The strength of these two dynamics, refusal and the sudden birth of new political imaginary, is such that there is even a question mark over whether Salmond’s SNP can survive the new political maelstrom.

Yet political commentators, especially in the English and American owned media, pretend that nothing has changed. For them, it’s just politics as normal. More middle aged men in suits exchanging insults – a battle where the protagonists are Alex Salmond and former Labour minister and No figurehead Alistair Darling.

I became interested, by contrast, because I sensed that something politically special was taking place. You can see it in the involvement of artists and cultural creators – radical theatre directors like David Greig and journalists like Joyce McMillan (not the usual suspects) – and from the imaginative excitement among students conveyed to me by my niece, Rosie Scott, who is in her final year at Glasgow Art School and drawn to stay in the city by its cultural vibrancy. I felt that at last there could be an opportunity to shake to the core “the foundations of Britannia as a pompous, blue-blooded colossus”, as Niki Seth-Smith from openDemocracy put it.

Mighty and militant movements against Thatcher such as the 1984-85 Miners Strike and the poll tax rebellion shook the colossus but could not bring it down. Parties of the left could not overcome the obstacles of the electoral system to pose a challenge to Labour from the left that might have prevented its submission to the neoliberal consensus. Could the Scottish movement for independence the stone in David’s sling that finds the lethal crevice in the armour of the Goliath?

This has not been a war of political machines. Certainly the Yes campaign, through the National Collective of Artists Supporting Yes, has benefited from the contributions of many brilliant cultural creators, while the No campaign has relied on planting negative stories about their opponents with the Westminster-style pedlars of political gossip. But the power of Yes is greater than its creative communication techniques.

The remarks of a young graduate from Caledonian University in Glasgow gave me an insight into what gives the Davids of the Yes campaign their unpredicted strength. Jim Bevington, born to English parents in the Shetland islands and living in Glasgow for the past five years, describes how he moved from being a rather passive opponent of independence to an engaged and enthusiastic activist in the Yes campaign. First, he realised that independence was not, as the media implied, about changing letterheads and rebranding Scotland. It was not even about nationalism. “I realised that something absolutely huge was at stake: the shake up and break up of the UK for the first time in hundreds of years. I needed to get informed and engaged. When I did get informed, going to the Radical Independence website and then to one of their conferences, I realised that it’s not just about how bad the UK is but about people’s ideas about what an independent Scotland could be like… fresh new ideas that have no prospect of being implemented in the UK but would have every prospect of being implemented in an independent Scotland.”

This is the feasible hope which draws people to get organised in Comrie, in Ullapool, in Troon, in virtually every neighbourhood across Scotland to share their ideas, to work out how they want to shape an independent Scotland. The dynamic of the process is self-organised, galvanised by the simple idea that every citizen resident in Scotland can vote for a different kind of society – not, as in most elections, just for a choice of elites. The possibility of independence is a challenge to Scottish voters to take themselves seriously and to give substance to the hopes they have shared informally with friends and neighbors.

What has built the self-confidence to take up that challenge to shape a new future, rather than bumble along with the familiar but imperfect present? The answer shines clearly from any direct experience of the Yes campaign in action. It is a strikingly generous-spirited, creative, diverse and plural movement, with a concentrated sense of common purpose. It has many platforms, including both the official Yes Campaign of politicians and national organisations and the Radical Independence Campaign (RIC), whose volunteers have canvassed working class communities that have been ignored by politicians for decades.

A variety of different campaigns bring different constituencies to the activities of RIC: the energetic, always-present Women for Independence; the strategically vital Labour for Independence, which now has the support of many of Labour’s leading figures. Then there is the Jimmy Reid Foundation, an influential think tank committed to action as well as words, led by human dynamo Robin McAlpine who manages to speak to fifteen meetings a week, going to bed in his words “exhausted and tearful” but still managing to exude energy and enthusiasm to all who meet him. The Foundation has brought together the ideas for a new Scotland coming from local meetings into a book-length manifesto: The Common Weal.

All these tributaries feed a populist movement that does without a charismatic leader. It is a populism organised through and around the people, in all their particularity. Its power lies in its many voices, in conversation with each other and with strangers, and the way that the Radical Independence Campaign takes a critique of some ghastly feature of UK government policy or structure and then turns the argument powerfully towards a fresh new perspective and positive solution.

An argument for independence based on escaping the London housing bubble, for example, becomes the positive case for Scotland to have the macro-economic powers to create a new kind of sustainable economy, creating socially useful jobs and based on a variety of forms of economic democracy.

Similarly, from a critique of Britain’s imperial role in the world and the one-dimensional nature of Scotland’s international relations so long as Scotland is part of the union, radical supporters of independence move to a liberating vision of the opportunities opened up by joining a network of nations. They explore a wide range of collaborations which take the debate far beyond the notion of ‘separation’ and a single, closed, national sovereignty. With the example of the Nordic Council in mind, they point to the feasibility of autonomy being the basis of a shared and pooled sovereignty and a chance to balance out power across our archipelago.

Whether this intellectual as well as organisational energy and associational power will on Sept 18th, produce a majority for Yes is uncertain. I, and many more English people than is publicly acknowledged, hope it will. But it is clear that there is no going back to the old politics, neither in Scotland nor across the UK. And this is about more than a new unstoppable surge of activism. Robin McAlpine tells of a campaigning granny who came up to him at the end of a pro independence demo and said, “When this is over, Robin, I’m naw going back to ma sofa.” She’s speaking for millions whose imagination has been changed. There are several historical comparisons that could be made: the awakening, for example, of the feminist imagination in the early 70s, which changed society forever and began a still-unfinished revolution, driven by a sense of glimpsed but as yet unrealised possibilities. The consequences of the closely fought independence referendum, with the likelihood of a result that will not be decisive and will serve to further open and deepen rather than close the debate, poses a very real threat to the UK’s ruling elites.

These elites have always ruled through an unwritten constitution: that is the secret of their power and its unbroken longevity. As Margaret Thatcher famously proved – with Charter 88 sounding the alarm – unwritten rules known and made only by those with power means that those at the top can do what they like, protected by an opaque membrane of taboo.

Two historic features of the British political system gave a kind of sacred quality to these unwritten rules, making the idea of a challenge unspeakable. The first is the Crown in Parliament, which enables the prime minister and his or her executive unhindered access to prerogative powers – to declare and conduct war, to make a huge number of appointments and so create a powerful patronage machine. More than that, the sovereignty of the Crown in Parliament gives any government with a stable majority the ability to do things through ordinary legislation – like dismantle local government as Thatcher did – that would be impossible in a properly constituted state.

The other, related source of taboo is the ‘union’ between the nations of the UK, which protects the Westminster parliament against real democracy and self-government. The strength of the Yes campaign and the fact that it is already spreading across the borders and boomeranging back (as I write, readers of the magazine that I co-edit, Red Pepper, are organising a train coach of English Yes supporters to go to Glasgow and give whatever practical and symbolic support that they can) will mean that the unwritten constitution will be talked about and questioned.

The taboo of hundreds of years has been broken. Nothing can stop this, however closely the main parties conspire to restore a reverential silence. But on both sides of the border, whatever the result of the referendum, we must do more than talk about the constitution and challenge its unwritten rules. In England and Wales we must follow the inspiration of the Yes campaign in Scotland and treat the fact that the union’s future is seriously in doubt as an invitation to imagine a different kind of England and a different kind of Wales, and different relations between and within our self-governing nations. We can already see in Scotland how the collective act of imagining a new social order turns disheartened subjects into the architects of a new constitutional settlement. Having been told for years that they did not want freedom and could not handle it if they had it, they have learned that they are willing and able. It is past time the rest of us learned the same lesson.

This column is based on my forward to a very useful e-book, 42 Reasons to Support Scottish Independence, by Adam Ramsey