Brian Quinn says most fans support his club's stance

Uefa has threatened clubs with disciplinary action as it clamps down on racism, bigotry and sectarianism.

And Quinn said: "We mustn't throw away our chances of success through the misbehaviour of a small number.

"Do they really want to see Celtic penalised, with the possibility of having points deducted?"

Celtic stress they have been working for years to stamp out songs with references to Irish Republican paramilitary groups like the IRA.

City rivals Rangers have also been working to rid themselves of Ulster Loyalist paramilitary chants.

A very few have argued that we are interfering with their right to free speech Celtic chairman Brian Quinn

But the Ibrox club still found themselves fined and censured last season for the behaviour of fans during their Champions League tie against Villarreal.

Quinn warned that Celtic could even be forced to play home matches away from Celtic Park if Uefa was to find their fans at fault.

And, with the Scottish champions travel to Old Trafford next week to face Manchester United in the Group F opener, he has issued a tough message.

Quinn said that fans "cannot really be called supporters if they continue to jeopardise our progress in Europe by singing songs and chants that are offensive to the great majority of our supporters.

"I have received many letters on this matter. The great majority fully support the stance taken by the club.

"A very few have argued that we are interfering with their right to free speech or that they do not need lectures from the likes of me on how to behave.

"Both these comments are wide of the mark.

"The right of free speech has to be balanced against the rights of others, especially in this case those who find the songs and chants in question unacceptable and damaging to Celtic's good name.

"I don't do lectures. As my recent letter shows, I do appeals to supporters' sense of good behaviour.

"I repeat that appeal: please do not jeopardise our prospects in Europe but instead act in such a way as to maintain the reputation of our fans for passionate support and decent behaviour.

"Finally, this is not a message intended only for European games.

"It applies equally to domestic matches, home and away.

"Let's create an atmosphere that all Celtic supporters can enjoy as we follow and support our great club."