Swift action is required to "crush" any return of racism to football before it impacts on wider society, Prime Minister David Cameron said today.
The PM said he had seen for himself the influence that behaviour on the pitch could exercise over young children and others off it.
But, speaking at the opening of a Downing Street anti-discrimination summit with former players and football bosses, he expressed confidence that the good work of two decades in battling prejudice in the sport would not be lost.
Mr Cameron said: "If everyone plays their role, then we can easily crush and deal with this problem."
He told the panel, including former England stars John Barnes and Graeme Le Saux, that he often took his young son to local football matches and had seen the impact the game had.
"What happens on the field influences what happens off the field. You see children as young as six imitating the behaviour they see on the field," said Mr Cameron.
ITV experienced an on-air snafu covering the subject:
"So this is not just important for football, it's important for the whole country."
The Prime Minister said there were many "extraordinary role models" among professional footballers but that problems with racism had "crept back in".
"We want to make sure football is all about a power to do good, rather than anything else," he said.