It was late last Wednesday when Credit Suisse received a call from the Treasury asking it to pitch for the coveted mandate of advising on the future of the UK's three biggest banks, Royal Bank of Scotland, HBOS and Lloyds.

The Swiss-based bank had been invited, along with Citi, JPMorgan, UBS and Deutsche Bank, to present a plan to the Treasury to achieve financial stability with the best possible outcome for UK taxpayers before the market opened on Monday morning.