The Society of Black Lawyers hit out at Tottenham and the Football Association after repeating its threat to go to the police over what it regards as anti-Semitic chanting at White Hart Lane.
Spurs fans sent an open message of defiance to the SBL on Thursday night when they chanted "We'll sing what we want" and "Yid Army" throughout the club's 3-1 home win over Maribor in the Europa League. Despite being a club with a traditionally large Jewish following, Tottenham fans often refer to themselves as "Yids" or the "Yid Army" in chants during the club's matches.
Although Spurs claim otherwise, the SBL say the phrase is anti-Semitic and they have vowed to complain to the police under the Public Order Act if supporters continue to use the chant beyond the November 20 deadline it has set.
The SBL had monitors at the north London ground on Thursday night who heard the chants and on Friday morning it reiterated its commitment to report any such action to the police should fans continue their actions.
"We are not going to let go on this," SBL chair Peter Herbert said. "After November 20 there is a potential that people will get a criminal conviction. If they want to run that risk then fine.
"We are serious. We aren't in this for sensationalism. We think the vast majority of Tottenham fans are sensible and do not engage in anti-Semitism. It's a very small minority who obviously don't care about any offence. Their love of football is greater than their desire to deal with anti-Semitism."
Tottenham have refused to comment on the matter. The London club stick by the statement they released on Wednesday which read: "Our guiding principle in respect of the 'Y-word' is based on the point of law itself - the distinguishing factor is the intent with which it is used ie if it is used with the deliberate intention to cause offence.
"This has been the basis of prosecutions of fans of other teams to date. Our fans adopted the chant as a defence mechanism in order to own the term and thereby deflect anti-Semitic abuse. They do not use the term to others to cause any offence, they use it as a chant amongst themselves."
Herbert also accused the FA of a lack of interest in the Tottenham matter, saying: "This is an appalling abdication of responsibility by the FA. It's a complete disgrace that they have stayed silent on this. There is an inertia from the FA over racism and anti-Semitism. You can't go and complain about racism and anti-Semitism in Serbia and then have it happening in your own back yard."
Press Association Sport is awaiting reply from the FA over Herbert's comments.