The LMA spoke on behalf of Mackay on Thursday after the 42-year-old Scot and his right-hand man Iain Moody were alleged to have shared racist, sexist and homophobic texts when they worked together at Cardiff.

It explained Mackay's conduct by saying he was "letting off steam to a friend during some friendly text message banter".

That prompted widespread criticism from anti-discrimination groups, while Cardiff said Friday that the 'friendly banter' defence 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 LMA's statement, for which they have since apologised, was published following Moody's resignation as sporting director of Premier League side Crystal Palace on Thursday after a file alleging misconduct during his time with Cardiff was sent by the Welsh club to the Football Association.

According to a report in Britain's Daily Mail, the file alleges that both Moody and Mackay, who was sacked as Cardiff manager by Malaysian owner Vincent Tan in December 2013, sent a series of racist, sexist and homophobic text messages to one another during their time with the Welsh side.

Two months after Mackay's departure, Moody was fired by Cardiff before going on to join Palace's staff

The LMA statement questioned the timing of the Mail's revelations, which appeared to have scuppered Scottish boss Mackay's hopes of succeeding Tony Pulis as manager of south London club Palace.

However, Cardiff insisted Friday the LMA had known for months about the offensive texts concerning Moody and Mackay, saying they were "complicit in the attempt to conceal these messages", of which there were "many more" than the two Mackay had admitted sending in Thursday's LMA statement.

- 'Duty to report' -

"That the LMA has sought to criticise the club for the timing of the report to the FA is preposterous, because the offensive communications have been in the knowledge and possession of the LMA for many months," Cardiff said.

"When the messages came to light, over three months ago, the club strongly encouraged and advised Mr Moody and Mr Mackay to deal with the issue directly with the FA.

"It was made clear to them, and their LMA-appointed lawyers, that the nature of the communications meant the club was under a duty to report their findings to the FA if they did not take appropriate action themselves."

Earlier on Friday, the LMA apologised for its original statement, saying it had not meant to "trivialise" issues of racism, sexism and homophobia.

But there was support for Mackay from veteran QPR manager Hary Redknapp.

"I am not condoning what he has done but he is not a bad person," Redknapp said. "He has not murdered someone, is not a rapist or a paedophile, he has made a mistake but that should not finish his football career."

Mackay guided Cardiff to the Premier League after a 51-year absence from English football's top flight.

After he was ditched by Cardiff, Mackay launched a �7.5million ($12.4 million, 9.4 million euros) legal claim against Tan for compensation but dropped the claim in May and apologised to the Bluebirds' owner.

Earlier this week Palace were fined by the Premier League for their part in the 'spygate' saga involving Cardiff last April.

The Premier League determined Palace had breached their 'good faith' rule by obtaining information about Cardiff's team ahead of their 3-0 win when the two clubs were relegation rivals.

Cardiff complained that Moody had contacted their employees for information in the build-up to the game.