Rangers used to refuse to sign Catholics. Celtic were an outpost of Hibernian pride and hostility to Scot land's Protestant majority. The ugly underbelly of Scottish sectarianism may have mercifully stopped short of bombs and guns, but was exposed when the two sides clashed. The so-called "Auld Firm" teams had "auld" tribal loyalties.

But with the Rangers team not only featuring Catholics, but genuinely Roman ones, times have changed. The internationalisation and commercialisation of soccer have shown up parochial prejudices for what they are. When the two teams meet at the refurbished Hampden Park national stadium in Glasgow today for the Scottish Football Association cup final, it should be a healthy sporting rivalry.

But it won't be.

The hopes that the vast support for Scotland's two dominant teams had moved with the times were dealt a severe blow on May 2nd, when Rangers went to Celtic Park to clinch the Premier League championship.

There was a pitch invasion, the referee was hit bloodily in the face by a coin, the city erupted with nearly three times its normal level of violent incidents that night, including an at tack on the referee's home, and the trendy face of the new Glasgow took a severe bruising.

It was a dispiriting event. Four days before Scotland's election, it provoked much soul-searching about some grim realities lurking behind the country's new-found confidence. It did at least ensure that kick-offs will never again be scheduled in the evening for BSkyB television, allowing drink to be downed and emotions to be raised throughout the day.

For the administration at Celtic Park, it showed that the club's determination to get rid of sectarian tribalism is going to take longer than it had reckoned. That determination has been given a high profile over the past three years in a campaign known as Bhoys Against Bigotry - The "Bhoys" being Celtic's traditional attempt to spell with an Irish accent.

The singing of sectarian songs is now a rarity at the Parkhead ground, not least because the stadium itself has been completely refurbished, is all-seated, has far more women attending and the largest family enclosure in Britain. A more important explanation is that those leading the singing face expulsion from the ground, with season tickets cancelled and long bans. Rangers too has been expelling hundreds from Ibrox.

Celtic officials take pride in the more intolerant chants being drowned out by songs that celebrate the club's Irish heritage: The Fields of Anthenry or The Celtic Song, but when the team travels to away matches, where bigotry cannot be countered with bans, those chants come back.

Simply ejecting bigotry from the stands, however, then puts it on the streets outside, where the night of May 2nd showed it does not cease. That is why Bhoys Against Bigotry has developed an anti-prejudice teaching programme with Glasgow teachers, which is now being used by most educational authorities in Scotland, including schools as far away as the Orkney Islands.

Branded with the Celtic FC shamrock, it lets children from five to 14 explore issues of friendship, learning about differences between people, then growing up to secondary level to explore the advantages of living with cultural diversity.

Getting the message right is a tricky task for Celtic, with its roots firmly in the west of Scotland's Irish community, and of course the support of football clubs anywhere in the world remaining fundamentally tribal.

One of the streets beside the stadium is named after Dalriada, the ancient kingdom of the Scots-Irish in the south-west of Scotland

Alongside the blue and white St Andrew's cross of Scotland, the club always flies the Irish Tricolour. To some, steeped in the politics of Northern Ireland, that is provocative and inflammatory. To Celtic, it is celebration in a positive way of dual identity, just as people are coming to terms with their shifting allegiances to Scotland and Britain.

"It's a positive identity that the club feels it has no need to apologise for," says a source at the club, his anonymity perhaps a sign of continuing nervousness about the issue. "We believe that is a totally different issue from bigotry. What we've tried to do is establish people's rights to their own cultural identity. Compared with bigotry, that's a difficult message to get across. It's a medium- to long-term project."

"Bigotry is not the sole domain of football," says another at Parkhead. "It has far more wide-ranging aspects to it. It's embedded in many parts of Scottish and Irish society."

The problem for Scotland's main football clubs is that while they seek to modernise and establish themselves on the European and world league, that wide-ranging bigotry continues to embed itself primarily in the support for their teams.