Mr Flavel had stepped down by mutual consent and with immediate effect, according to Paul Thwaite, the interim chief executive of NatWest Group, which owns Coutts.

"In the handling of Mr Farage's case we have fallen below the bank's high standards of personal service", Mr Flavel said. "As chief executive of Coutts it is right that I bear ultimate responsibility".

He is the latest scalp claimed in the row sparked by the high-net-worth bank closing the former UKIP leader's account.

The story first came to light when the BBC inaccurately reported the account was shut as he did not meet Coutts's financial thresholds.

Documents obtained by Mr Farage subsequently showed his political beliefs and connections formed part of the rationale.

The NatWest chief executive, Dame Alison Rose, resigned early on Wednesday morning, just hours after the NatWest board had expressed full confidence in her.

Read more: Dame Alison Rose's ousting is a sad end to a distinguished career with no obvious successor

The chancellor and prime minister, representing the bank's largest shareholder - the taxpayer - said she did not have their confidence.

On Tuesday evening Ms Rose admitted a "serious error of judgement" in discussing Mr Farage's banking arrangements with BBC business editor Simon Jack.

Mr Farage has called for further sackings and said the whole board of NatWest, who own Coutts, should go.

Responding to Mr Flavel's exit, Mr Farage said it had only been "a matter of time" before he stood down.

"The ultimate responsibility for the dossier de-banking me for my political views lies with him," he said.

"I even wrote to Mr Flavel twice before going public and didn't receive an acknowledgment."

Mr Flavel is expected to be replaced by Mohammad Kamal Syed, who is currently the head of asset management at the bank, on an interim basis until a permanent successor is found.