Late in 1999, UBS presented a new strategy that set out the Swiss bank’s future as an integrated group spanning private banking, investment banking and asset management. One of the executives charged with selling the vision to investors was its new chief financial officer, Luqman Arnold.

Eight years on, Mr Arnold has changed his mind. The UK-born banker, who was forced out of UBS late in 2001, is now agitating for a shake-up at the bank that could ultimately lead to it being broken up.