Business Secretary Vince Cable has expressed his concern over the appointment of high-profile investment banker Robert Diamond as chief executive of Barclays, saying it raised questions about the safety of UK banks.

Appearing on the BBC's Today Programme, Cable said that the decision was a reflection of "the wider policy question about how our banks can be made safe."

He expounded on his anxiety for the security of tax-payer money that supported banking operations, saying "We are worried about this combination of casinos and traditional banking and the banking commission will be coming up with some strong conclusions on that."

Although Barclays weathered the recession without direct taxpayer supported bail-outs, it did benefit from central bank liquidity, which was extended to the sector.

Analysts are of the opinion that the move to install Diamond as chief of Barclays was a deliberate stand against the Vickers inquiry - the coalition government's commission chaired by Sir John Vickers - to asses if UK banks' investment and consumer operations should be split.

The commission will be reporting its findings next year.