Dame Alison, CEO of Coutts parent NatWest, has already stepped down over the affair.

New NatWest interim chief executive Paul Thwaite announced the departure of Mr Flavel this afternoon.

Mr Flavel will exit immediately by mutual agreement.

The row started after Mr Farage had his banking facilities at Coutts withdrawn. Initially Coutts / NatWest insisted it was because he fell below the wealth threshold for an account with the upmarket bank but later it transpired that Mr Farage’s political views had been a factor in the decision to ‘debank’ Mr Farage.

Mr Farage was called a "disingenuous grifter" in internal Coutts documents which were released to Mr Farage under privacy laws.

Coutts is well known as a private bank but also has a significant and growing Financial Planning arm.

It is understood that Mohammad Kamal Syed will take the role of interim CEO at Coutts and for the NatWest's wealth businesses.

In a statement, Mr Flavel said that it was right that he took “ultimate responsibility.”

Dame Alison Rose, CEO of the NatWest banking group, resigned yesterday after sharing of information about Nigel Farage’s relationship with Coutts. She came under pressure to resign from Nigel Farage and MPs who had shared concerns over her sharing inaccurate information with the BBC.

Dame Alison apologised yesterday for the breach of information. Initially the board backed her but she decided overnight to go.

Statement from Paul Thwaite, NatWest Group CEO: “I have agreed with Peter Flavel that he will step down as Coutts CEO and CEO of our Wealth Businesses by mutual consent with immediate effect. Whilst I will be personally sorry to lose Peter as a colleague, I believe this is the right decision for Coutts and the wider Group.

"I have asked Mohammad Kamal Syed (subject to usual approvals) to step into the role of interim CEO of Coutts and our Wealth Businesses. Mo has extensive Wealth Management experience and is the ideal person to lead Coutts through this difficult time as we begin the search for Peter's replacement.”

Mr Flavel said in his statement: "I am exceptionally proud of my seven years at Coutts and I want to thank the team that have built it into such a high performing business. In the handling of Mr Farage’s case we have fallen below the bank’s high standards of personal service. As CEO of Coutts it is right that I bear ultimate responsibility for this, which is why I am stepping down.”