I WANTED to make this column all about Christmas. I wanted to write about how I thought it important that over the next two weeks all of us take a break from politics, that we put all that anger and anxiety behind us, and spend time with people we love over the holidays, doing things we love – talking, eating, drinking, laughing.

In the end, though, I couldn’t in all good conscience write that column. I couldn’t write about how great we’ll all feel if we only just switch off from the infernal buzz of politics for a fortnight and recuperate in the arms of our family with good food, good wine and good conversation.

How could I write that piece when at this time of year family and friends come to visit me in Glasgow and I briefly see the city through their eyes while we walk from restaurant to pub to shop? Full bellies, presents under our arms, wending our way back home a little tipsy.

My out-of-town friends and family see what I see every day, but they see it fresh. I notice the disbelief and upset in their eyes at the homeless people shivering on every street corner. I see their sense of shame as they walk by yet another fellow human being without a roof over their head.

I feel the same shame and upset as they do, but if you’re from Glasgow or Swansea or London or Liverpool, you come to live with it. It doesn’t mean you don’t care, it’s just that to make it across the city you have to block out what’s happening around you, or look the other way, at least a little bit, at least for some of the day. If you didn’t, you’d be in a permanent state of tears and distress.

‘You come to live with it’. What a terrible thing to say, but it’s true. It feels unforgivable – and it is – but that’s why I couldn’t write some end-of-year feelgood piece. How can I say ‘let’s just think of ourselves’ when there’s people out there with nothing and no-one? When homeless people are dying on the streets of Scotland? When homeless people across Britain have been killed, raped, urinated on, robbed, set alight, humiliated and beaten?

If an alien landed and looked at us in the western world they’d be bewildered. We’ve sent humans into space, we’ve built the internet, eradicated diseases, we’ve got people on Earth as rich as Croesus, but yet we cannot look after the most vulnerable in our society.

Homelessness has long eaten away as my conscience – even as a little boy. I was brought up in a rough, poor housing estate in Northern Ireland during the seventies. Alcoholism, violence, domestic abuse, going to bed hungry – it was all part of life. But I’d never seen homelessness until one summer I was taken to London by ferry and coach, aged about seven.

From the moment we got out at the bus station, I saw ragged people huddled in doorways, begging. I’d no idea what had happened to them. How could others be walking past them when they seemed sick and scared and so desperate. Why were doctors or police not helping them? Where were their friends and family?

Years later, as a grown man and a journalist, I tried hard to keep my mind turned towards homelessness – to write about the experience of people on the street, how they got there, what needs to be done to help, how society had failed them. And believe me society has failed the homeless.

We hear stories of homeless people being con artists – phoney beggars with money in their pockets and a comfortable home, fleecing us hardworking types of our money. Quite possibly there’s a handful of people like that – it’s just that I’ve never met them and I’ve interviewed and spent time with hundreds of homeless people.

After a while, you learn that the stories of people who end up sleeping rough on the streets follow an horrifically predictable path. And you think: there but for the grace of God go I. I struggle to think of any of the rough sleepers I’ve spoken to who haven’t spent time in care. Most were victims of some dreadful childhood abuse. There’s psychiatric problems. They had useless, dangerous parents. By their teens, they’re into drink and drugs. After the care system, they’re alone in the world. Prison beckons. Prostitution beckons. Heroin beckons. Oblivion beckons.

For others – the folk who end up sofa-surfing on friends’ couches, or living in a hostel – homelessness came with a lost job, a divorce, a missed payment, a break-down. Most of us are just one pay-check away from the street if you think about it. If you lost your job, lost your partner and lost your home – where would you be tomorrow?

Like many, I do what little I can. You can support charities, make donations. I give money straight to the folk on the street. Many would disagree, and take the patrician view that I’m aiding drug taking or drinking. Often I’ll buy someone a cup of tea and a sandwich and slip them a few quid. They’ll eat, get warm, and if they want a can of beer – who the hell am I to judge? If I was reduced to living on the streets, a bottle of vodka or a needle of heroin might be some momentary, desperate escape from the hell of my life.

Homelessness is a failure of all politicians, although some are self-evidently better than others: homelessness did fall under the last UK Labour government, only to rise again under Conservative austerity. Nevertheless, no political party has truly tried to fix the problem and save lives.

The annual number of rough sleepers in Scotland is about 5,300 – around 700 every night. The homeless charity Shelter has began legal proceedings against Glasgow City Council for failing to help homeless people.

Is it beyond our wit to turn a few of the myriad abandoned properties in our cities into night-shelters or hostels? Can a unit of police and social workers not be tasked to comb cities looking for vulnerable people to help? Can some political leader make ending homelessness a real priority, not a glib platitude?

It’s one of the oldest wisdoms on Earth: you can only judge a society by how it treats its weakest members. With Christmas, the time of fellow-feeling, just around the corner, we need to reflect and judge ourselves. By any standard, we’ve failed.

Neil Mackay is Scotland’s Columnist of the Year