It is amazing how the Green Brigade, that noisy and sometimes militant band of Celtic supporters, can split opinion - even within the walls of Celtic Park itself.

Speak to some people and they’ll tell you they like this boisterous mob with their booming, reverberating chants at Celtic Park.

Speak to others, and you’ll find contempt for the Green Brigade, a so-called pro-IRA bunch with nothing but hatred for Britain born of a tortured Anglo-Irish history.

The divided jury on the Green Brigade is perfectly summed up by Neil Lennon himself. Over the past two years the Celtic manager has been gushing in his praise of these Celtic supporters, while also casting criticism in their direction.

Lennon, to the Green Brigade’s disgust, took some Celtic supporters to task in May 2011 for a sudden upsurge in pro-IRA singing, though he didn’t specifically mention the content of the chants.

This is all germane once more given that, last Saturday, the Green Brigade boycotted Celtic’s match against Dundee United at Parkhead, citing “police harassment” of their members, as well as an alleged lack of support for them from within their own club.

In a statement the Green Brigade criticised Celtic CEO Peter Lawwell and Lennon for failing to aid them in their grievances.

In fact, the central thrust of the current controversy from Celtic’s point of view – an issue of safe standing and “lateral movement” inside Celtic Park– is duly ignored by everyone.

The fact is, whenever the Green Brigade are debated, the squabbling quickly alights on whether political chanting of any kind should be allowed inside a football ground.

Personally, I deplore songs about the IRA. Some Celtic fans sing pro-IRA songs, while some Rangers fans also refer to the IRA in chants. I’d happily bin the entire repertoire. It is embarrassing to hear this cack inside Scottish football stadiums.

In the case of the Green Brigade, the issue is complicatedly bound up in their view of Celtic’s Irish heritage. For some of their members - though not all - Celtic FC is a symbol of the historic struggle of the Irish.

You may well ask: what has this got to do with football? The answer, I would say, is nothing. Yet football supporters all over Europe - not least those of Rangers and Celtic - have cited political or religious antecedents as grounds for their chanting at football games.

At Celtic Park, in my experience, some reports of the Green Brigade’s “persistent pro-IRA chanting” are grossly exaggerated. For example, on two recent visits to Celtic’s ground I’ve heard not a whit in this direction.

Not so when Celtic travel on the road. On these occasions such slogans can often be heard. For some reason Tynecastle in Edinburgh is a tipping point for this type of Celtic fans’ chanting.

It has been a rule of thumb for years that “being on the road” brings out the zealots in the Celtic and Rangers supports. Rangers have seen vast improvements in terms of eradicating bigoted singing at Ibrox, but can still be embarrassed by fans’ chanting away from home.

Celtic FC have an obvious problem with the Green Brigade. It is this: the club wants to preserve its celebration of its Irish roots; Celtic also loves the Green Brigade for their impressive acoustics at Celtic Park. But the club also feels insecure and wrong-footed in that hazy area where Irish eulogy ends and anti-British sentiment begins.

On some occasions the Green Brigade were the unjust whipping boys for Celtic, such as during their anti-Poppy protest in November 2010.

I write this as a proud Poppy-wearer and someone who has a deep respect for its symbolism. But I ask you: what is the terrible crime in fans of Celtic or anyone else protesting against the Poppy?

These days there is an anti-Poppy sentiment right across British society. I profoundly disagree with it, but are we to ban it and lock ‘em all up?

Celtic’s response to the Green Brigade protest that day was absurd - the club reacted like the fans had been screaming poison and threatened to track down the villains and confiscate their season-tickets.

Having stated that I detest IRA chants, I also know that such slogans are a complication, in Glasgow as elsewhere.

If Uefa, in strict terms, wanted to outlaw this type of stuff from football, I’m not sure where they would start, let alone finish. Real Madrid and Barcelona, with their fans’ competing political and “separatist” agendas, could be a start.

Then Uefa could head to Italy via Glasgow, and then take in that hotbed that is the former Balkans while trying to strip away all this baggage.

The Green Brigade precisely represents football’s problem, where “the culture” of a club is both encouraged and resisted.