A quartet of former investment bank heads at UBS were today hit with accusations of "gross negligence" as they faced questions from MPs over the Swiss bank's role in the manipulation of Libor.

The UK's Parliamentary Commission on Banking Standards, led by chairman Andrew Tyrie, this morning grilled the former UBS group chief executive Marcel Rohner as well as former investment banking heads Huw Jenkins, Jerker Johansson and Alex Wilmot-Sitwell.