Story highlights Celtic versus Rangers, the Glasgow "Old Firm," is one of the fiercest rivalries in world football

On Sunday the "Old Firm" play each other again for the first time in the new season

But the 396th "Old Firm" clash will be played amid plans by the government to end bigotry at the game

The singing of provocative songs could be outlawed in 2012 and carry heavy penalties

Robert Marshall is the burly, landlord of The Louden Tavern, a pub located in the west end of the Scottish city of Glasgow, on the south bank of the same Clyde River that was once used to ferry coal and steel to the great shipbuilding companies that in the past made this area an industrial powerhouse.

There is no doubt as to which soccer team Marshall and his clientele give their loyalties. Decorated in the team colors of red, white and blue throughout its interior and situated only a stone's throw from the famous Ibrox Stadium, the bar is overt in its homage to Rangers Football Club.

In fact, to call any establishment that has a stained-glass window in honor of Jim Baxter -- a Scotland midfielder who played for the "Gers" in the 1960s -- and a six-foot club badge painted on the ceiling a mere drinking hole is a disservice, it is closer to a shrine.

Its position around the corner from the Glasgow Orange Order -- a Protestant fraternity who still march once a year to celebrate the victory of King William III over the Catholic King James II in 1690 at the Battle of the Boyne -- may be a mere coincidence, the allegiance of its regulars to Rangers is not.

Across town, on the Gallowgate road, Tommy Carberry pulls pints in Bairds Bar, a building daubed in the green hue synonymous with Celtic Football Club. The pub sits a mile-or-so from Celtic Park -- the 60,000-seater home ground of the 42-time Scottish title winners -- and is a much-loved stopping point for fans attending the match.

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This area of the east end is known locally as the "Barras" -- slang for the barrow markets -- and is inextricably linked with an influx of Irish immigrants who settled in the area in the 19th century to escape the potato famine.

Inside, a myriad of patrons dressed in green and white jerseys pack into the ale house, where Bodhran drums adorn the walls, to sup their stout and sing along to Irish music which jingles from the speakers. Many have traveled across the Irish Sea as part of a fortnightly pilgrimage to see the action in an arena dubbed "Paradise" by such faithful followers of football.

Celtic wears its Irish and Catholic heritage very much on its sleeve -- or chest to be more exact, as the club's four-leafed clover badge sits on the left breast of its players -- which is maybe not surprising for a team founded by a member of a Catholic religious order in 1888.

The two landlords -- who remarkably, are childhood friends -- represent two of Glasgow's communities in a microcosm, one passionately British and Protestant, the other proud of their Catholic and Irish heritage, a division which mirrors the sectarian lines of Northern Ireland, loyalties forged over centuries of war and strife.

Like their fathers before them, Robert and Tommy's cultural background almost dictated which of the city's two giant clubs they would support. Allegiance to Rangers or Celtic carries a cultural significance above a mere love of the beautiful game for many nestled around the banks of the Clyde.

The Old Firm

It is one of the ingredients that makes the meeting of these two teams, over 90 minutes of football, so special. Celtic versus Rangers is one of the fiercest rivalries in world football.

The coming together of the two communities in the cauldron of a stadium to cheer on their sides, as well as proclaim their identity with songs and banners, creates a unique and febrile atmosphere. On one side of the arena the red, white and blue of the British Union Flag. On the other the green, white and gold of the Irish tricolor flag.

The clash -- which normally happens four times every season in the league alone -- even has its own nickname: The Old Firm.

It is usually highly charged and often controversial. In the past players celebrating a goal by making the sign of a cross or miming a flute from a Protestant marching band have provoked serious trouble in the stands.

On Sunday the "Old Firm" play each other again for the first time in the new season. But the 396th edition of the rivalry will be played amid plans by the Scottish government to stamp out what it says is religious bigotry associated with the fixture.

It follows what was a tumultuous season in 2010/ 11, where many felt the sectarian nature of the fixture escalated to unacceptable levels.

Though both clubs are committed to creating tolerant atmosphere's within their home arenas, the singing of provocative songs has often been present among a minority of fans.

"The Billy Boys" chant -- which includes the line "we're up to knees in Feinian [a derogatory term which means Catholic terrorist] blood" -- and songs glorifying the IRA [Irish Republican Army] are just two examples of anthems that have dogged the match for as long as memories go back. Other common targets include the pope and the British queen.

In the early part of 2011, these sentiments -- which are usually only in the background -- came to the fore.

Rangers were admonished and received a ban by UEFA -- the governing body of European football -- for sectarian singing in a game against Dutch side PSV Eindhoven, while the family of Celtic's Catholic manager Neil Lennon was put under 24-hour police surveillance when live ammunition and a parcel bomb were sent to him in the post.

The government decided it was time to act.

The proposal

Roseanna Cunningham, the lawmaker for Community Safety and Legal Affairs in Scotland, told CNN: "We've had a problem with sectarianism in Scotland for a long time, and it is most manifest -- though not solely -- in football. What we saw last season was a ratcheting up of the tension to a level we'd not seen before ... and we decided that we needed to tackle this specifically with legislation."

The draft law that is being assessed before its anticipated introduction in 2012, will create offences from behavior which "incites religious, racial or other forms of hatred at football grounds" including "threats intended to incite religious hatred" according to an official government statement.

Arguably this could include the provocative songs sung by a minority of fans at Old Firm games and the penalties, if found guilty, could be tough.

"The penalties will be anything from a fine to five years in prison. We want to make sure people are aware of how seriously we take this," Cunningham added.

"The law [if passed] can't change a culture, we know that ... but we hope, ultimately, it will result in the better behavior of football fans without the necessity of using the law."

It is a sentiment that has been welcomed by the local police force who have long experience of handling the Old Firm fall-out.

"Unfortunately, when you go to these fixtures you'll hear some of the most horrific chanting of a sectarian nature which is aimed wholeheartedly at offending people from another religious persuasion," Campbell Corrigan, Assistant Chief Constable for Strathclyde Police, told CNN.

"Some of these songs include people singing about others' deaths or the death of iconic people in religion. We can't have that and I think there is now a need for us to underline our commitment that we're going to tackle this."

In other quarters, however, the new law is raising anxiety.

The response

Outside the red-brick facade of the 1920s-era main stand at Ibrox, the amiable John MacMillan admires the terraces that have provided such compelling drama down the years.

MacMillan, the general secretary of the Rangers' Supporters Association, told CNN he fears the law could criminalize legitimate fans. "I have no objections to legislation being brought in if it is going to be helpful but not if it is not enforcible.

"We are trying to get these songs defined by the police and the Scottish parliament, but no one yet has been able to say here is a list of songs you shall not sing. What is acceptable and what is not -- will it be down to the police officer on the scene? We don't know where we are at the moment, it is a gray area.

"The singing and the chants are sometimes not very nice, from both sides I may add, and we just wish we could eradicate this from the game ... many good supporters and the clubs on both sides are making in-roads in this.

"I would just question whether there is any need for this legislation," MacMillan added.

It is a view shared by former Celtic striker Andy Walker, who played for the side in the 1980s and 90s. "All of the songs that are now deemed to be offensive were around when I was playing, we just used to let it wash over us," Walker told CNN under the watchful gaze of the Jock Stein statue that stands at the main entrance of the Celtic Park in memory of the manager who led the side to European Cup glory in 1967.

"Now we're in the era where people are desperate to be offended, we have a justice minister who thinks it offensive to make the sign of a cross or to sing the national anthem. I think there needs to be a lot of fine tuning before the new bill comes into play as I think the police use the Old Firm occasion to highlight issues that actually affect the whole of Scottish society: sectarianism, drinking and domestic abuse. I'm not sure what the players can do to make these better."

The government may argue that through the use of CCTV and by working with the clubs involved it will be possible to successfully prosecute offenders, but some critics worry the move is being driven by forthcoming elections and that consequently the plans have not been thought through.

The future

Back in The Louden Tavern, as punters dressed in football kits trickle in from the drizzle to catch Rangers' latest game on the television, Marshall shakes his head before speaking in a broad Glaswegian lilt [which is hard to do justice to in prose].

"I don't have a problem if they're banning the songs that should be banned, I do have a problem if they're trying to stop freedom of speech. Rangers fans have got their act together 100% and I don't think they get credit for that.

"It's just political correctness stuff. Rangers and Celtic fans all grew up with each other, go out with each other, marry into each other. I really don't understand what the politicians are trying to do. Maybe they're trying to deflect from other serious issues.

"I don't hear offensive songs in the Ibrox Stadium, and I mean that in the broadest sense, not just from the Rangers point of view."

Despite their perceived differences, Marshall's apathy is shared wholeheartedly by Carberry at Bairds Bar, who turns down the music to the disappointment of his punters to speak to CNN.

"There are no Rangers supporters that come in here, so nobody will be offended by what is being sung. Same with Rangers' pubs.

"[But even if they do sing] what is acceptable and what is not? What is sectarian chanting and what is not? You have to remember a lot of these people are singing about their grandfathers and their time in the Troubles in Ireland.

"If you're singing about your grandfather in the IRA, or your grandfather in the UDF [Ulster Defence Force] ... if you sing that at a football match, you're going to be arrested for that? I think they're taking on too much.

"Celtic and Rangers football clubs, they depend on us and we don't want the wool to be pulled over our eyes. My friend Robert in the Louden, he's Rangers and I'm Celtic, and we love these games."

There is maybe confusion among some as to what is offensive in the context of the Old Firm but for Marshall it is very simple.

"There's only one Celtic song that offends me," Marshall says with a smile. "It's when Celtic sing 'we are the champions!'"