In October, during a tense meeting with then chancellor Kwasi Kwarteng at the UK Treasury’s office in the centre of London, the chief executives of Britain’s high street banks bemoaned the fact that Goldman Sachs and JPMorgan were using customer deposits to fund risky trading operations.

The UK’s ringfencing rules, imposed in 2019, allow banks to raise up to ￡25bn in retail deposits before they must be separated from their investment banking arms. That limit, the domestic banks told Kwarteng, puts them at a clear disadvantage in a fight with Wall Street insurgents hoovering up UK savings.

JPMorgan, who views the UK as a testing ground for low-cost digital banking, found the complaint ridiculous. A person close to the bank pointed out that they already had the largest consumer bank in America for gathering deposits. In the US, the Glass-Steagall Act of 1935, which prevented deposit-taking banks from dealing in securities, was fully repealed in 1999.