My mum will vote No on 18 September, and she will do it, partly, out of grief. I will vote Yes, and I too am doing it, partly, out of grief.

We are both grieving for the same person: my dad, who died in January this year, a few months after his 80th birthday. My dad was English. My mum is Scottish. And so I am both.

It is early September, 2014, and I have just arrived at my mum’s house on the west coast of Scotland to find a ‘No thanks’ poster in the window of her porch. This catches me off guard. I have never really spoken to my mum about politics, although I have sometimes wondered whether my dad, like me, could have been won over to supporting independence, had he been able to engage in the arguments. He was a socialist and, I believe, an internationalist; as a younger man he would have read the Common Weal book from cover to cover, probably making neat little notes in the margins. Most of my conversations with my dad were about politics, in some way or other. When I moved away from home he communicated with me by posting me newspaper clippings, usually from the Guardian or Observer. But in recent years this all stopped, as his concentration, then his memory, then his capacity for ideas and language, slowly slipped away. So I can only speculate.

It’s very clear, though, where my mum stands, even though much of her thinking has already drifted into the same fog where the names of her family, or objects around the house, or the details of daily routines, increasingly elude her. ‘This is so important,’ she tells me, emphatically, pointing at the No Thanks badge on her blouse. ‘I want Scotland and England to stay together. And I don’t like that man, he tells lies.’ At the time I don’t register the pain in her voice. I try to make a joke of it, thinking maybe I can win her over. ‘Scotland’s not floating out to sea, Mum,’ I say. ‘And a lot of people think the two countries will have a better, more equal relationship after independence. I grew up in England, remember, but I’m voting Yes.’ That man, I’m guessing, is the First Minister: ‘And it’s not about Alex Salmond,’ I add, ‘there are loads of people involved in the independence campaign, from lots of different backgrounds and political parties. There’s even a group called English Scots for Yes.’

But she isn’t taking it in, and as soon as I do notice she’s upset I drop it. Later that day I read a message from my sister, which she sent before I went to mum’s house but I somehow missed. ‘I don’t recommend discussing the referendum with Mum,’ it says. ‘She’s extremely worried about it to the point of not sleeping. Somehow she equates the idea of England and Scotland separating with being separated from Dad, and it’s as if the SNP are somehow denigrating their marriage.’ Oh.

My first reaction, I’m not proud to admit, is irritation. I think my mum has been taken in by unionist smears, by the relentless focus on Salmond and the constant description of Yes campaigners as ‘nationalists’, a choice of words designed to make us sound like a bunch of Bravehearts with a grievance rather than a broad, progressive political movement. I think to myself, how dare these people trick my mother?

But this is arrogant, and a little heartless. The present is such a blur for my mum that a decision as firm as this must be deep-rooted. I’ve always known that, as a young couple, my parents faced prejudice from both the English and Scottish side of the border. My mum, my sister reminds me, had always distrusted the SNP. Better Together didn’t need to plant any ideas in my mum’s mind. She made it up years ago and, to be frank, until relatively recently I might well have been on her side. I too have faced anti-Englishness in my time here, and, for a while, struggled to separate it from the Yes campaign. Back when I was a journalist sitting on the referendum fence, every time I wrote something about independence or identity the comment thread of the Scotsman website quickly filled up with snide, inaccurate comments about me from smaller-minded Scots. It was assumed that I am wholly English, southern English probably, that the Eaton part of my name means I must be posh (the school is spelled E.T.O.N, idiots – I went to a state school in Carlisle) or that my double-barrelled name means I must be posh (no, it means my name is Eaton and I married a woman called Lewis), or that my Scottish wife must be posh, from St Andrews probably (Dalgety Bay actually, and no, not the ‘posh’ bit). Blah blah blah. It was stupid, pointless, exasperating and delayed my conversion to Yes by about a year.

My mum, in her late 70s and only plugged into the debate via our mainstream media, was never going to make that leap. More importantly, what she now needs to survive, to find a path through the fog, is as much stability and certainty as she can hold on to. Trying to convert her would potentially be psychologically damaging, particularly if it were her son doing it. For all kinds of complex reasons, her decision is absolutely valid.

It strikes me that there will be many, many thousands of similar cases. Consider this: if there is, as some predict, a turnout as high as 90 per cent in this referendum, that means many, many people who do not normally vote, who perhaps have never voted, and are therefore engaged with the process in ways that do not fit the usual rules of political discourse. Some of their motivations will seem inexplicable, contradictory. But they must all be considered valid. Because we’ve all got to live together afterwards.

For the whole of my childhood, my dad was a teacher at a state school in Carlisle. He believed passionately in the NHS and the welfare state, and the right of every child to a free education. He was a member of the Labour party until he died; one of my tasks after the funeral was to cancel his membership. He hated Margaret Thatcher’s government, privatisation, and the creeping reforms to education that forced schools to behave like businesses. And I idolised him. When, as a teenager, I began to realise that he was wrong about certain things (he was, for example, guilty of homophobia, like so many men of his generation, although that changed in later years) it was confusing and traumatic for me. While I have found my own identity as I have grown, all of my political ideals can be traced back to his influence. When I was 18 I joined the Labour party. The Guardian is still my newspaper of choice. Every time I go off on a rant about how I am a citizen, not a consumer, I hear my dad’s voice. My quietly spoken mum was in his shadow a little politically. While I knew she voted Liberal Democrat she never had a lot to say about it, but she taught me tolerance and compassion. She got the homophobia thing long before he did.

It was only a couple of weeks ago that I began to appreciate how much grief has shaped my journey to Yes. It hit me while reading an interview with Irvine Welsh in the Sunday Herald, where he described talking to his friend Danny Boyle about the Olympics Opening Ceremony he directed, which became one of 2012’s big cultural talking points. ‘It was almost like a Requiem mass for something that was lost,’ said Welsh. It made him ‘really angry and really sad’. Boyle, he said, felt much the same.

It was, in other words, an expression of grief, for a Britain that seemed to have been killed by Thatcherism and neo-liberalism. It has been fascinating to watch the debate raging among Scottish Labour party members, between the No voters who cling on to the idea that their party can still be a force for good in Westminster, and the Yes voters who see independence as the only way to save what’s left of Clement Attlee’s legacy, to show the rest of the UK that there’s a fairer, more compassionate way of doing things than unfettered capitalism.

There are, it is said, three stages of grief. The first is disbelief, shock and disorientation. The second is experience of loss, which can involve anger, depression, often denial. The third is reintegration – reconciliation, acceptance, accepting your newfound reality and moving on. The UK’s disintegrating political union is often compared to a marriage in crisis. I wonder if it is more like a death in the family. Some people, on the left in particular, are in a state of denial, others in a state of acceptance.

This analogy will annoy Labour No voters, no doubt – being told you’re in a state of denial is probably a little condescending. There is, I’m sure, a case to made that the union is not only alive and well but still in good health, although I’ve yet to hear it be made very convincingly, and certainly not by anyone from Better Together, who – perhaps fatally – have never felt the need to inspire anyone, preferring negativity, bluster and dismissal. So apologies, No voters, it rings true for me, albeit for obviously personal reasons. But not just because of my dad. I think I was grieving as far back as 1994, for John Smith, the man who might have been Labour prime minister instead of Tony Blair were it not for his heart attack. I remember the shock and denial I felt at the time, robbed of the hope I’d invested in this man as a young, idealistic party member. The anger and depression came a year later, with the victory of Tony Blair (a man I distrusted from the beginning) in the Clause IV debate. And yes, I do know that, without that vote, Labour might have been unelectable. But that’s a conversation for another time. The point is, back then it was a body blow for me, and made me give up my party membership. The whole thing still sits uneasily with me. Power at what cost?

The acceptance, the reconciliation, took longer. I avoided politics for years, seeing in it only disappointment and betrayal by ambitious, smooth-talking men. And then the independence debate came along and I found a new, hopeful political life, as have so many other people. The day I finally stopped grieving for John Smith, I think, was the day I finally understood that, beyond a very small and rightly shunned minority, the Yes movement really had nothing to do with nationalism, that there was nothing in it to threaten my British identity, nothing that would force me to compromise, or make excuses for my half-English, half-Scottish hybrid personality. Instead it was about citizenship, democracy, accountability, genuine social inclusion and fairness – and in a country small enough that it all seemed possible, in which grassroots campaigners had real access to the people in power.

My experience of grief, this year, has been closer to home. A big part of grieving for a lost parent is fear of being alone in the world, feeling incapable of coping without a guiding hand. Experiencing this now, it often seems to me as if Scotland is going through something similar. The bag has been packed, a date has been set to leave home. Someone important has died, but others remain. Leaving would be a difficult decision, except for, oh yes, the incessant shouting in the background, a bullying, hectoring relative telling us that we’re useless, that we don’t know what we’re doing, that we’ll never amount to anything without the family to take care of us. The sooner I’m out of that home, frankly, the happier I’ll be. At time of writing, at least half the population seems to agree.

My real family is a happier place than that, but I can’t help seeing parallels between learning to cope without my dad and Scotland’s journey to independence. Here’s one that’s very much on my mind at the moment. As with all families, grief involves a complex re-negotiation of relationships. My sisters and I are the parents now, watching over my mum as best we can, in ways we don’t always agree on. I discovered last week that everyone in my immediate family who has a vote in this referendum will be voting No, apart from me. It was a difficult thing to accept, but it was a stark reminder that, after 18 September, we will all need to find ways to get on. Around half the population is likely to feel a sense of shock and denial not unlike the first stage of grief. That’s a frightening thing. My mum is genuinely terrified of a Yes vote. I am scared of No, of the potential sudden death of so much of the hope I’ve felt over the past couple of years, a hope I’d not dared to feel since the early 1990s. Compassion and empathy will be essential in the days to come, as thousands of people figure out how to cope with their loss.

Andrew Eaton-Lewis was group arts editor of the Scotsman and Scotland on Sunday until January 2014. He is currently a freelance producer, PR and cultural advocate, and was one of the creators of All Back to Bowie’s at this year’s Edinburgh Fringe (allbacktobowies.com).