FOOTBALL leaders, politicians and police united yesterday to condemn the mayhem that broke out during the Old Firm match.

Stewart Regan, chief executive of the Scottish Football Association, spoke out in strong terms against the "inflammatory and irresponsible" behaviour shown during the clash between Celtic and Rangers, which he said crossed the boundaries of acceptable conduct.

He blamed the unedifying sight of two of the country's most recognisable and respected coaches, Ally McCoist and Neil Lennon, angrily confronting each other after the game for stoking the flame of an already highly charged atmosphere.

Announcing an investigation into the incidents, he added: "I was both saddened and deeply embarrassed to witness the scenes that unfolded during what is supposed to be Scottish football's flagship fixture: these images were broadcast around the world and show our game in a poor light.

"In an age of austerity and financial hardship, football must try harder than ever to restore its image as the national sport, extolling pride and passion. It fails in this regard."

Mr Regan praised the match official, Calum Murray, for retaining his composure during the chaos but Celtic's chief executive Peter Lawwell said he took issue with some elements of the SFA boss's statement.

Mr Lawwell said the club would co-operate fully with any investigation but added: "The team remained composed throughout what was, at times, a difficult game, and the fact that only three of our players were booked is evidence of that composure and discipline, which provided the foundation for us to go and win the match. They should be congratulated in this regard."

Martin Bain, chief executive of Rangers, blamed the tension on incidents at previous matches when two Rangers players had been subjected to "extreme verbal abuse" in the tunnel and around the dug-out area.

He said McCoist had been acting in defence of one of the team's players, while Lennon said he had sat down with the Rangers assistant manager after the match and the matter was now closed.

Mr Bain said: "We as a club take our social responsibilities very seriously. As regards drunken, violent or sectarian behaviour – either at Old Firm matches or in the wider community – we are at one with the police and Government. Indeed, we work closely with Celtic through the Old Firm Alliance and other initiatives to tackle sectarianism."

However, Strathclyde Police Assistant Chief Constable Campbell Corrigan warned of the knock-on effect of aggressive behaviour from club officials and players and said that at half time, police had asked the security team of both clubs to ask the managers to calm down.

He said: "If anybody thinks the activity of the people involved in the game doesn't have a huge impact on the crowd, whether it be in the ground, in the pub, or on the other side of the world, they are hugely naive."

The issue also sparked a rare show of unity from politicians at Holyrood when Conservative Party leader Annabel Goldie raised the problem of the rise in domestic abuse that has been linked to Old Firm matches.

Alex Salmond said Celtic and Rangers had both proved to be capable of expressing solidarity with each other through community programmes, during the funeral of former Celtic manager Tommy Burns, when Rangers manager Walter Smith and McCoist had helped carry the coffin, and at the recent commemoration of the Ibrox disaster. But he added: "The disgraceful scenes of last night cannot be ignored.

"In terms of how people's actions have an impact on society, the fans at football matches are representatives of their clubs, the players are role models for society and the management of football clubs have a particular responsibility."

Ms Goldie said there was a "huge moral obligation on football clubs, their management and players to set the highest examples of responsible behaviour".