George Osborne raises concerns with Obama administration over US banking regulator's damning indictment of Standard Chartered

George Osborne has raised concerns with the Obama administration about the approach of US banking regulators to allegations of sanctions busting by one of Britain’s biggest banks.

Mr Osborne is understood to have spoken to his opposite number Tim Geithner, the US Treasury Secretary, after New York Department of Financial Services broke ranks with other regulators and published as damning indictment accusing Standard Chartered of hiding more than $250bn of transactions linked to Iran.

Tonight the Treasury refused provide details of the contents of the call but it comes against a backdrop of increasing unease in Whitehall over what some see as growing political attacks on British banks from across the Atlantic.

Earlier today the Governor of the Bank of England Sir Mervyn King appeared to question the motivation of the New York authorities in publically shaming Standard Chartered – before investigations had been concluded. As a result at one stage more than 25 per cent was wiped off Standard Chartered share price yesterday.

“I think all that the UK authorities would ask is that various regulatory bodies that are investigating a particular case try to work together and refrain from making too many public statements until the investigation is completed,” Sir Mervyn said.

The Mayor of London Boris Johnson went further – effectively accusing the New York authorities of trying to damage Britain’s banks to benefit their American competitors.

“You can’t help wondering whether all this beating up of British banks and bankers is starting to shade into protectionism; and you can’t help thinking it might actually be at least partly motivated by jealousy of London’s financial sector — a simple desire to knock a rival centre,” he wrote in The Spectator.