Chelsea have told fans attending the Capital One Cup final against Tottenham on Sunday that they will take the strongest action against any fans involved anti-Semitic chanting against Spurs supporters.
The Stamford Bridge club, who last week suspended fans over a racist incident on the Paris Metro before the Champions League game at PSG, delivered the warning in a statement on their official website.
The statement, written after consultation with both the Metropolitan Police and Spurs, urged Chelsea fans to "keep their support positive."
It said: "For a small minority, this game has historically brought a deeply unpleasant and unwanted level of anti-Semitic abuse, which has no place in football or anywhere in society."
And it warned that terms used "as a form of identity" by Tottenham fans -- a reference to the word "Yid," which has been adopted by many Spurs fans -- can also cause deep offence.
"Opposition supporters using terms as a form of identity is no excuse for abusive chanting or behaviour," the statement said. "The club asks that all supporters realise such actions cause huge offence to those around them.
"If we receive evidence that supporters have engaged in anti-Semitic or any other form of discriminatory chanting or behaviour, we will take the strongest possible action including supporting criminal prosecution."
Earlier this week, the chairman of anti-discrimination group Kick It Out urged police to "swamp" the Capital One Cup final in order to prevent racist and anti-Semitic chanting.
Lord Herman Ouseley said: "We have always had a lot of complaints when Spurs play Chelsea.
"We have got to have a high [police] presence. Anti-Semitism must be tackled with the same vigour as all other forms of discrimination.
"Personally I would swamp Wembley. The police used to say once: 'We are going to swamp Brixton [in south London], we are looking for the muggers. Any black person, we are going to pick them up and take them off the streets.' Swamp Wembley and start to flush out these people."
On Sunday, West Ham fans were filmed singing an anti-Semitic chant on a train as they travelled through Stamford Hill -- a north London suburb with a large Jewish population -- before the club's game at Tottenham.
Ouseley praised Chelsea for their swift response to what happened in Paris and noted that West Ham had said they would ban any fans found guilty of anti-Semitic chanting for life, but stressed that more was needed from Britain's football authorities.