Business secretary Vince Cable has conceded the UK's biggest banks may not be split along "crude lines" but instead firewalls could be introduced to separate retail and investment arms.
Cable is a fierce critic of the way in which banks such as Barclays, RBS and HSBC run what he calls "casino" investment banking operations, underpinned by an implicit taxpayer guarantee of their high-street banking in the UK, the FT reports.
The appointment of Bob Diamond as Barclays' chief executive has infuriated Cable and reopened the debate about the make-up of the UK's banks. Diamond, head of Barclays Capital, will now take charge of the whole bank, including its retail operations.
The business secretary said Britain's "universal" banks had to be made safe, but conceded: "Splitting the banks can mean different things."
He said "subtle" methods - rather that a "crude" separation of investment and retail banking - could work, such as placing "firewalls" between the two arms.
'We have better oversight'
50th anniversary of moon landing
Technical and behavioural factors
The Value Perspective