Cardiff have called for League Managers' Association chief executive Richard Bevan to resign following his organisation's defence of Malky Mackay's use of racist texts as 'friendly banter'.
The Welsh club described the LMA's criticism of the timing of the release of the dossier regarding Mackay and former head of recruitment Iain Moody to the Football Association as "preposterous".
They also said the 'friendly banter' defence of Mackay's text messages was "reprehensible".
"A manager's behaviour should demonstrate to players and other employees under his control that discrimination in any form is unacceptable,'' said a Cardiff statement released through the club's lawyers Mishcon de Reya.
"We therefore find it entirely reprehensible that the LMA should itself put out a statement which seeks to dismiss deeply offensive racist comments as 'friendly banter'.
"If that is the view held by the LMA, as appears from its statement, we consider that Richard Bevan's position is untenable and we call for his resignation."
The Daily Mail had earlier published examples of the explicit text messages, though it was unclear who precisely is responsible for sending many of them.
The LMA released a further statement on Friday morning apologising for the wording of its first statement.