NatWest (NWG) boss Alison Rose has resigned from her position after admitting to being the source of an inaccurate story about Nigel Farage's finances.
Shares in the company fell nearly 4% after the anouncement on Wednesday.
In a statement released early on Wednesday morning, NatWest Group chair Howard Davies said: "The board and Alison Rose have agreed, by mutual consent, that she will step down as CEO of the NatWest Group. It is a sad moment.
"She has dedicated all her working life so far to NatWest and will leave many colleagues who respect and admire her."
In a statement of her own, Rose thanked her colleagues "for all that they have done", adding: "I remain immensely proud of the progress the bank has made in supporting people, families and business across the UK, and building the foundations for sustainable growth.
Earlier, Rose said she made a "serious error of judgment" when she discussed Farage's relationship with private bank Coutts, owned by NatWest Group, with a BBC journalist.
Davies initially said the board members had decided the chief executive retained their "full confidence" but her position became ever more uncertain after the Chancellor and Downing Street were said to have "serious concerns" over her conduct.
An emergency board meeting was called late on Tuesday night to determine her future, with the announcement of her resignation coming a few hours later.
Last week, Farage presented evidence, in the form of a 40-page dossier, that his account at Coutts had been closed partly due to his political views conflicting with the bank's values.
BBC Story
The evidence obtained from the bank through a data request contradicted a BBC News story, which initially claimed that the account closure was motivated by commercial reasons only, citing Farage's failure to meet a £1 million borrowing requirement.
The BBC and its business editor Simon Jack apologised, saying the reporting had been based on information from a "trusted and senior source" but "turned out to be incomplete and inaccurate".
In a statement, released alongside Davies on Tuesday evening, Rose said: "I recognise that in my conversations with Simon Jack of the BBC, I made a serious error of judgment in discussing Farage's relationship with the bank.
"Believing it was public knowledge, I confirmed that Farage was a Coutts customer and that he had been offered a NatWest bank account.
"Alongside this, I repeated what Farage had already stated, that the bank saw this as a commercial decision. I would like to emphasise that in responding to Jack's questions I did not reveal any personal financial information about Farage.
"In response to a general question about eligibility criteria required to bank with Coutts and NatWest I said that guidance on both was publicly available on their websites. In doing so, I recognise that I left Jack with the impression that the decision to close Farage's accounts was solely a commercial one."
Davies said the "overall handling of the circumstances surrounding Farage's accounts has been unsatisfactory, with serious consequences for the bank", before promising an independent review, which will be made public.
FCA Steps In
Sheldon Mills, Financial Conduct Authority (FCA) executive director for consumers and competition, said it had raised concerns about breaches of confidentiality by Coutts and its parent company NatWest.
He also emphasised the importance of a "well-resourced" independent review to investigate the matter "swiftly" and "fully", adding: "On the basis of the review and any steps taken by other authorities, such as the Financial Ombudsman Service or Information Commissioner, on relevant complaints, we will decide if any further action is necessary."
NatWest, formerly known as Royal Bank of Scotland, was bailed out during the 2008-2009 financial crisis. The taxpayer's stake in the company has gradually reduced over time due to several share sales by the Government, with the latest bringing its ownership down to 38.6%.
A string of Tory MPs, including former cabinet minister David Davis and Saqib Bhatti, the Conservative Party's vice-chairman for business, had also called for Rose's resignation.
She has also resigned from co-chairing the government's Energy Efficiency Taskforce and the Net Zero Council.
NatWest's board of directors announced that Paul Thwaite, the current chief executive of the company's Commercial and Institutional business, will take over Rose's responsibilities for an initial period of 12 months, pending regulatory approval.
The board said in a statement that a further process to appoint a permanent successor will take place "in due course".
City minister Andrew Griffith will meet Britain's largest banks on Wednesday morning to address concerns related to customers' "lawful freedom of expression".