A wall of silence pierced only by Slaughter and May has descended across the City with nine out of 10 of London’s top corporate advisers refusing to comment on whether they strike sweetheart fee deals with their banking clients.

As Legal Week went to press, only the famously independent magic circle firm would confirm that it does not charge higher rates when banks are passing on the bill to their corporate clients, as opposed to the own-account work paid for by the bank.