Orangemen need a "clause four" moment to prove they've changed.

I remember my first experience of an Orange Walk. I was in a student flat in Edinburgh's Leith when I was woken at some unearthly hour of the afternoon by loud banging. It sounded like someone was demolishing the tenement.

I craned out of the window to see curious folk with orange sashes and bowlers shouting offensive remarks about the Pope, throwing sticks in the air and hurling threats at residents waving the Irish Tricolour from their windows. The banging was from the Lambeg Drum, an instrument designed to resonate off tenement walls and instil fear.

I later learned that I was dossing in a supposedly Catholic area of town and this was one of many Orange walks. I'd had a sheltered atheist upbringing in which such things as religious sectarianism were unknowable. This was one aspect of 20th century working class culture that didn't appeal.

The "walk" was more like an army of occupation, which is pretty much what the Orange Order is, or used to be, all about: it is about promoting and defending Protestant supremacy. The paramilitary standards, flutes and drums were primarily about intimidation.

Later when I was working for the BBC in the 1980s I frequently faced the Big Daddy of Protestant sectarianism: the annual July 12th celebrations of the Battle of the Boyne in 1690, in which King Billy - William of Orange - overwhelmed the Catholic supporters of James V11th (James 11 in England).

I suppose this was celebrating community in one sense, but it mainly seemed to be about getting very drunk and trying to provoke fights. In fact I vividly remember seeing what could only be described as a riot in central Glasgow with broken heads and windows.

I was amazed that this didn't dominate the evening news and the next day's papers. I was advised by a BBC colleague that the broadcasters tended to underplay these events in the interest of public safety and not provoking further violence.

I don't believe this was ever editorial policy in the BBC, but it seemed to me to be a form of self-censorship. It was as if Scotland just couldn't face up to its sectarianism, which until pretty recently we frankly couldn't.

And so we come to this weekend's Orangefest, a celebration of the "history and culture" of the Grand Orange Lodge of Scotland which will take place in George Square with Glasgow Council's blessing on Saturday.

The Order presents itself as an "ethnic minority" with a right to hold its own cultural celebration. Let's hope other tribes don't come to celebrate theirs.

We're assured that breaking heads will not be part of Orangefest, but the big Lambeg drum will be. "Big Drums are part of our culture", said Edward Hyde, Grand Master of the County Grand Orange Lodge of Glasgow on BBC radio yesterday. The Black Skull Corps of Fife and Drum will be there, along with face-painting and no doubt a bouncy Londonderry Castle.

Orangefest also allows the boys to hold an extra Orange walk this year through the centre of the city. Will there be songs that could be illegal if sung at a football ground?

There has been outrage at all of this. Yesterday alone 20,000 people signed a petition calling on the event to be disowned by the council and even banned. "The Klu Klux Klan wouldn't be allowed to celebrate its culture in George Square" said one. "The Order is no more the voice of Protestantism than the Provisional IRA is the voice of Catholicism, or ISIS of Sunni Islam", said a comment piece on Bella Caledonia.

The SNP opposition on Glasgow City Council don't seem too happy either at giving civic reception to the Orangemen. Nationalists are still smarting from the events of September 19 last year, when Loyalists invaded George Square tearing up saltires and giving Nazi salutes to the Yes supporters.

And it's true that the Orange Order is a sectarian organisation in that it doesn't allow Catholics to join; not that I imagine they'd be queuing up so do to. But I'm not sure banning is the right response. If every organisation that insisted its members abide by its core beliefs were to be outlawed then we would be banning lots of religious organisations.

I loathe everything that the Orange Order has stood for in the past. But it claims that it is no longer a militant organisation and that it no longer seeks confrontation with Catholics. People will scoff at this, and perhaps with justification.

However, it is not all that long ago since the Church of Scotland itself was militantly anti-Catholic. In the 1920s, Kirk figures openly called Catholic immigrants "vermin" and "carriers of disease". The Kirk is no longer a sectarian organisation, though it still expects its members to be Protestant.

Religious sects and far-right organisations like the Orange Order thrive on persecution. Denying them expression only strengthens them, lends mystique, even martyrdom. Putting them in the spotlight - like putting the former BNP leader Nick Griffin on Question Time - exposes them to ridicule and scrutiny. It shows us what they really are.

So I say: let the Orange Order hold their festival on Glasgow, provided it is peaceful. Police Scotland say that it is "low risk" and who am I to argue with that? Let's see what it is about their culture that they really want to celebrate.

No doubt we will hear all about how Mozart was a freemason and how Dr Barnardo, of the children's homes, was an Orangeman; and that King Billy was fighting against dynastic tyranny.

It's true that William of Orange was, indeed, responsible for the Glorious Revolution of 1688 which led to the Bill of Rights, the end of absolutism and the foundation of our democratic constitution.

The Jacobite rebellions are still celebrated by some Scottish nationalists. Yet Bonny Prince Charlie was attempting to restore to the UK the Stuarts and reverse the achievements of 1688; at least that's how many Lowland Scots like the philosopher David Hume saw it.

Somehow, I'm not sure this is quite the history that the Orange Order thinks it's celebrating. But fair dos. Organisations can change. However, they need to make positive signs that they have reconciled themselves with their own sectarian past.

So here's a challenge to the new, inclusive, non-sectarian Orange Order. How about a statement on Saturday that it would support repeal of the 1701 Act of Settlement that prevents a Catholic from acceding to the UK throne? Call it the Orangemen's "clause four" moment.

What better way to show that the Order really is simply celebrating the positive aspects of Protestant culture and history, and not sectarian division?