“Serious questions about George Osborne’s actions are raised in a congressional report on investigations into HSBC.

“The Chancellor urgently needs to clarify whether he thinks that there are circumstances in which it is acceptable for financial service companies to potentially break the law and avoid prosecution. And he should clarify if he had received representations from HSBC prior to writing to Federal Reserve chair Ben Bernanke, seeking to sway the US investigation.

“It is not acceptable for any institution to place itself above the law, however powerful or financially important. It is hard to envisage circumstances where the Chancellor of the Exchequer should be using his office to interfere in a criminal investigation.”