Matthew Westerman, who left HSBC last week, is not the first big relationship banker to try to help change the way the UK bank serves its corporate clients and, judging by its recent history, he will not be the last.

In its bid to generate more revenues outside its traditional strengths in lending and debt capital markets, HSBC has turned to a great many external bankers in the hope that "having them in the room" will equal lucrative advisory mandates.