English soccer's governing body issued a public apology last week to Eniola Aluko and her fellow England women's international Drew Spence after comments deemed "discriminatory on grounds of race" were made to them by the team's former coach Mark Sampson.
In a speech to the FA Council published on its website on Thursday, Clarke promised his organisation would put in place "whistleblowing or grievance procedures" by December to allow individuals to come forward with complaints.
Clarke appeared before a parliamentary panel last week in which Aluko said the FA had an agenda to protect Sampson and its reputation, and the chairman described the inquiry as "a bruising personal experience".
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"We recognised the mistakes we had made, and hoped we could demonstrate our good intentions in how we had addressed an undeniably serious set of allegations. We failed," Clarke said. (http://bit.ly/2iBNbiv)
"The judgement of the politicians, the judgement of the media and most importantly the judgement of the public was very clear – we had failed Eniola Aluko, Drew Spence and Lianne Sanderson.
"We have apologised to them and I reiterate that apology again today."
Clarke said the lack of trust was brought about partly by the FA's large and complex remit and by the public's perception of a lack of competence within its ranks.
That the organisation had an all-white board and senior executive team and only one black, Asian, and minority ethnic (BAME) head coach across the England teams, also contributed to the perception it lacked diversity, despite efforts to increase inclusion, he added.
Clarke said the FA needed to change its "fundamental climate" by increasing inclusion and allowing senior players and managers a role in its governance, while making the organisation "simpler and cleaner" to win back the trust it had lost.
In response to Clarke's statement, Herman Ouseley, chairman of pressure group Kick It Out, called for wholesale reform and greater involvement of black and ethnic minorities.
"Across the rest of the game, it is clear that black and minority ethnic people are not trusted to be in the boardroom, senior management, leadership, coaching, technical and administration positions – and this is not a new realisation," he said.
"It is inconceivable that the people who botched the first investigation are still in their posts," he added, in an apparent reference to FA technical director Dan Ashworth and human resources director Rachel Brace.
(Writing by Simon Jennings in Bengaluru and Neil Robinson, editing by Ed Osmond)
