Players' chief Gordon Taylor has rejected criticism of footballers who spit on the pitch, insisting the practice is an unavoidable consequence of strenuous physical activity.
The charity Keep Britain Tidy are writing to Taylor, as chief executive of the Professional Footballers' Association, saying players should set a better example and that youngsters are copying their heroes and spitting on the streets.
But Taylor told PA Sport: 'The Tidy Britain Group is a worthy charity but it is offensive to suggest my members are not setting a good example.
'The group's target is to keep the streets tidy but the football pitch is a different arena.
'They should appreciate that footballers run about six miles every game and sometimes they need to clear their air passages.
'I'm not suggesting it looks pleasant but it is sometimes unavoidable and and the only reason it is apparent is because the cameras focus close up on players.
'You would see the same thing with any athlete involved in strenuous physical activity.'
The Tidy Britain Group has also called on players not to spit at each other - they polled just under 300 fans from 19 clubs around England and found they were overwhelmingly upset by the incident in which Bolton striker El-Hadji Diouf spat at Portsmouth's Arjan de Zeeuw.
Manchester United manager Sir Alex Ferguson was mentioned, for spitting out his chewing gum at the end of matches.
A spokesman for the organisation said: 'I've seen him throw gum on to the ground, and also just spit it on to the ground, at the end of the match.
'It's not a difficult thing we're asking him to do - just to wrap it up in a piece of paper and stick it in his pocket.
'We would be delighted if he wanted to help us in our of our campaigns - he is listened to and respected by tens of thousands of Manchester United and other supporters.'
On spitting on the pitch, he added: 'Football has done much to bring people together and combat problems such as racism. Now it is time to tackle spitting.'