The SBC today opened the banking reporting season with a profit boom that is likely to increase calls for a windfall tax on the sector, and revealed the surprise departure of second-in-command Ewan Stephenson.

A surge in interest rates around the world saw the global bank’s third-quarter profit jump by $1 billion to $6.5 billion, even beating Citi’s optimistic expectations.

While most of these profits have been generated outside the UK, political pressure to impose new taxes on HSBC, NatWest, Lloyds and the rest is likely to only increase.

Stephenson will be replaced by Georges Elkhedery as CFO, apparently suggesting he may soon succeed CEO Noel Quinn.

The former chief executive of Royal Bank of Scotland, who is credited with helping to turn around the collapse of the state-owned lender, was seen as a strong CFO in the City and his departure raises questions about the stability of chief executives.

Quinn has insisted he is “here for many years”, but chairman Mark Tucker is seen as a tough operator who may decide otherwise.

Tucker said Stevenson, who is paid £3.5m a year, “leaves with our best wishes”, in a rather blunt statement.

With new Prime Minister Rishi Sunak looking to plug a £40 billion hole in the public finances, banks could prove an easy target. Although he promised last year to cut the so-called bank surcharge from 8% to 3% while he was chancellor, his latest successor, Jeremy Hunt, has not committed to doing so.

HSBC has come under fire for being so-called “green” – claiming that advertising is greener than it actually is.

The Financial Conduct Authority has today proposed new rules to ‘ban’ the use of terms such as ‘green’ or ‘sustainable’ by City firms. Sasha Sadan, the FCA’s director of environment, social and governance, said in a clear statement to HSBC: “Greenwashing misleads consumers and undermines confidence in all ESG products. Consumers need to be confident that products that claim to be sustainable actually are.”

Signs of an impending recession in the UK led HSBC to set aside $1.1 billion in the quarter to cover possible defaults on customer loans.

His statement included an attack on the previous government’s disastrous “mini-budget” that sent bond markets crashing.

“Recent economic policy in the UK has led to a fall in the value of sterling and a sharp rise in government bond yields, increasing uncertainty about the future course of Bank of England policy,” HSBC said. “We are closely monitoring the impact of these developments and any implications for our business.”

Shares in HSBC fell 30p to 444p today. They are flat for a year.