Ian Clarke resigned from HSBC over alleged racism, frustrated at the speed and scale of the bank's response to a report he wrote alleging racism within its ranks.

He says banks are failing to deliver on promises to hire, retain and promote more Black executives, as prejudice and a reluctance to change stymie leaders' good intentions.

Born to a white mother and Jamaican father in London, Clarke was drawn to banking because of the opportunity it offered people without privilege.

He enrolled in HSBC's management training scheme in 2007 and rose through the ranks.

His report - "Project Speak Up" - looks at the state of diversity within HSBC based on interviews with around 100 colleagues.

"The bank keeps these numbers very closely guarded but the numbers that I uncovered suggested that we had just 90 black leaders in a firm of 226,000 globally. 90 black people in 226,000, across 65 countries, five of which are majority black countries. And that number has significantly reduced since then, currently estimated to be about 60 black leaders remaining with an HSBC group today."

While he welcomed the bank's initial response to the report Clarke says he became disillusioned by the pace of change.

Of the 11 Black and minority people in his sales team, he says nine have left HSBC in the last three years and none have joined to replace them.

HSBC did not comment on this.

"Slowly as I looked around the room I noticed the seats of my black friends emptying. I was on a team, a global team, global sales for transaction banking that had 11 black people on it and nine of those black people have now left."

It comes at a time when banks worldwide say they are trying to implement pledges to improve diversity, after the murder of George Floyd in police custody in the United States in May 2020 sparked global protests over racial injustice.

HSBC - Europe's biggest bank - said in July 2020 it aimed to double the number of Black staff in senior roles by 2025.

CEO Noel Quinn told Reuters recently the lender "saw no need to restate" that target.

Clarke however - says the bank is unlikely to achieve that goal under its current direction, and that the problem runs throughout the industry.

"I do not think if you're leaving it to people who don't understand these concepts to try and execute a strategy to fix them, I cannot see how that is anything more than performative allyship."