AR Brown, a former Labour voter who bitterly resents the party’s stance in the 2014 referendum, says Scotland’s radical progressives will be in a knife-fight with the UK’s radical conservatives over the next two years, and Scottish Labour needs to pick a side.

So, here’s the thing. For a long time I voted nothing but Labour, but I stopped doing that, and in 2014 I not only voted Yes but, for the first time in my life, I knocked doors in that campaign. It’s likely that I’ll be even more involved if there’s ever another chance to secure self-government for Scotland.

I don’t doubt that a fair proportion of Labour Hame’s readership after reading that first paragraph aren’t reading this one. We all know that there’s an impressive set of fortifications separating the Labour Party from those who voted Yes, and the guns on that bastion point both ways. Maybe there’s even a few people who will doubt my right to write anything on a site dedicated to progressive politics when I’m clearly a small-minded, parochial, anti-English bigot with no grasp of economic reality.

The problem with that is that I’m trained in academic research, I’m typing this in England, I build financial models for the banks and insurance houses, and I’ve never been a member of any political party – not even that one. And as I mentioned before, I used to be a Labour voter and a big part of my commitment to the Yes side was a strong desire to protect the remnants of the 1945 social democratic settlement secured by your party. In other words, apart from a difference in opinion about where the border should be a couple of years ago, I ought to be one of you.

We may not live in dark times yet, but the sun is going down and the stars seem shy in coming out. Progressives need to stand together now or be swept away by the tide of unpleasantness exemplified, not by the Brexit vote, with which I disagree but understand, but by the clear lurch of the UK to the authoritarian, nativist right in response to that vote.

I want the Labour party to function well in Scotland. I want your candidates for First Minister to be plausible and I want every constituency to be hard fought amongst as many parties as possible including yours. I don’t share the tribal disdain for your party that some of your opponents do, but I do resent some of the things that you have done to a degree that I can only describe as visceral. I’ll come back to that.

After the Westminster election of 2015 I heard Johann Lamont on Radio 4 asking for anyone who had forsaken her party to get in touch and making clear that she would listen. I got in touch, offering to talk all she liked but all I got was a baffled response from her office that led nowhere. My interpretation was that she clearly wasn’t expecting anyone to actually get in touch, she just wanted to appear to be open to ideas, to give the impression of listening.

After the Scottish general election I thought again about offering my tuppence worth, and indeed after a talk by your former staffer Simon Pia I thought I’d try again, so I sent a polite e-mail offering to talk at any meeting of my local CLP about bridging the gap between Yes voters and the Labour Party. I never received a reply, although I know the email was received, which only intensified my worry for your future.

So this is my third and final attempt at reaching out to you, and here’s what I need you to hear.

I was horrified by our attack on Iraq, I was exasperated by the grubby municipal politics of the early years of the last decade – especially by the usurious PFI programme – and I was aghast at Gordon Brown’s proposals for a national identity register, but the summit of my fury at your party is the way you approached our referendum of 2014. That was the decision in my life to which I have applied the most intellectual effort. I felt privileged to be trusted with the future of our country and keenly aware of the solemn weight of that responsibility and, perhaps subconsciously, I expected everyone else to feel the same way regardless of which way they decided to vote.

If you consider the notion of Scottish self-government absurd, impossible or criminal what comes next won’t make sense, but neither – to my mind – will the existence of Denmark as a self-governing entity of five and a half million highly educated, well organised, energetic, happy people.

From a party political point of view the referendum put you in a fantastically powerful position and with this power came, axiomatically, commensurate responsibility. The Tories couldn’t win the vote on their own. They relied on you to win it, and you could have extracted any price you cared to in return for your help. You could have demanded the reform of the electoral system, abolition of the House of Lords, reform of trust law or reform of company ownership rules – any one of which would have counted as massive forward movement for progressive politics. You could even have done something about the British class system. Demanding Crown dependency status for our country would probably put independence in the shadows for several generations, leaving the party-that-must-not-be-named as an etiolated seedling desperately seeking the sun rather than taking root in the limelight of European affairs.

Instead, as far as I can make out, you gleefully joined in the campaign to make the referendum itself a wretched, dumbed-down, tribal trench war with the ultimate aim not of improving the lives of ordinary people but of defeating your opponents. You behaved as if it was mathematically impossible to find any benefit in self-government, yet failed to explain why the last part of the UK to become self-governing, despite all its troubles, has never contemplated attempting to re-join that Union. Arguments presented as absolute and un-nuanced tend to fail basic reality checks and yours did just that. To make matters worse every single one of the skeletons you rattled at us two years ago has since clambered from the grave to dance a grinning Charleston round the country despite us voting as you exhorted.

So what can you do?

First off you have to decide if your approach in 2014 was a potentially fatal error or not and declare that decision loudly. If you decide that you’d do the same again then I really do think that you are finished, but that’s your call to make. Every human being has exquisitely tuned antennae for sincerity. If you do decide to apologise for the course you sailed during the referendum campaign then it has to be truly heartfelt and it has to have consequences that will initially be painful for you. There can’t be a hint of rebuke or grievance. Some of your recently retired representatives and former employees have hit this tone, but none of your actual elected officials’ public statements do – there’s calculation, triangulation and deference in every word.

Secondly, you need to live up to the ‘Scottish Labour’ name and become an actual party, or drop it and campaign proudly as plain Labour. We need to know who’s in charge, and even those of us who pay attention just don’t. As things stand your candidates for First Minister will have a leader in another nation to whom they answer and who is unaffected by decisions here. If you have a notion of our nation as having its own unique needs, that situation is ultimately untenable regardless of the qualities of the leaders involved.

And lastly – federalism. If you really want to keep giving CPR to that constitutional corpse you need to tell us what the complete end-to-end mechanism is for its delivery. If that process includes Labour winning a UK general election and a vote in the House of Lords then I think it’s only fair to say that we’re going to need atomic-level detail on how that situation might come about.

I don’t think it’s an overstatement to say that this is an emergency. Forces are afoot now that might see not just the post-war settlement but all the subsequent social advances swept away within a few years. Scotland’s radical progressives will be in a knife-fight with the UK’s radical conservatives over the next two years. There will be no place for moderates. James Wilson’s 1820 slogan seems likely to fit 2018 like a glove – Scotland Free or a Desert.

This is the time for decisive collective action and I’d love Labour to join in, but if you can’t, if you really think this is the moment to squabble about income tax, then you will have placed yourselves firmly and permanently in the opposite camp to mine.