Spurs fans who use the word "Yid" should not be arrested for hate speech, according to David Cameron.
The prime minister contradicted the Football Association which banned the word and threatened Spurs fans with arrest for using it at football games.
Cameron told the Jewish Chronicle: "You have to think of the mens rea (Latin for 'guilty mind'). There's a difference between Spurs fans self-describing themselves as Yids and someone calling someone a Yid as an insult.
"You have to be motivated by hate. Hate speech should be prosecuted - but only when it's motivated by hatred."
Use of the word "yid" by Tottenham Hotspur supporters is a complex issue. It is a way to respond to slurs by rival fans and as a way for Tottenham supporters to identify themselves to each other, like a greeting. It is not used as a tool for malice, they say.
The FA moved to designate the word in the same category of language as "n*****" and called for action to halt its use at football grounds. This stance was disputed by the White Hart Lane club which said the context it was used in was not to cause offence.
The Board of Deputies of British Jews said that "Yid" was always an offensive word, no matter the context, and backed football chiefs.
Vice-president Jonathan Arkush said: "We support the FA's stance in defining the Y-word as an offensive term and we hope that once and for all its use will die out.
"We strongly support the Community Security Trust's view that the FA should be applauded for seeking to take steps that will undoubtedly reduce anti-Semitism at our football grounds.
"Whilst we agree that not everyone who uses the Y-word intends to foment hatred, the board's view is that the Yword is nevertheless, offensive, which is why we hope that people desist from using it."
The Community Security Trust said: "We have consistently said that Spurs fans' use of the Y-word does not remotely compare with, nor in any way legitimise, the vile and unacceptable anti-Semitic abuse that is all too often heard from opposing fans.
"Ultimately, ridding football of anti-Semitism needs to involve Spurs fans voluntarily dropping the Y-word from their songbook."
Spurs fan Richard Hughes told IBTimes UK that the insulting meaning of the word was recognised by fans. But he said efforts to stamp it out would fail.
"It's never going to happen because they will be ejecting thousands of people from the ground," he said. "Even away at places like Chelsea, there are still 3,000 or so of us."