Mr Cameron used his veto last month to opt out of the treaty, arguing that the UK needed to keep its authority over financial services in the City of London.

BBC: EU summit: UK and Czechs refuse to join fiscal compact

In an existence of almost 25 years, the SFO has never commanded much respect from the police or from its counterparts at the Financial Services Authority (FSA), the City watchdog - whose own performance in taking action against financial wrongdoers is perceived to have improved from a very low base.

BBC: SFO: Can it survive Tchenguiz humiliation?

The extent of HBOS' problems were revealed in a week when the City watchdog, the Financial Services Authority, said it had raised concerns about the way the bank was being run as far back as 2002.

BBC: Darling defends bailout of HBOS