Bob Diamond is under pressure. On Tuesday, he will announce Barclays' results for the first time as chief executive. But the scrutiny will be intense, particularly after Credit Suisse Group last week reduced its target return on equity to 15% from 18%, blaming the new Basel III capital rules. Diamond's challenge is to persuade investors that the UK bank, which doesn't have the benefit of a highly profitable, low-capital-intensity private-banking business, can deliver similar returns.

The market is clearly sceptical, with the shares trading below book value. Diamond's problem is that Barclays likely ended 2010 with risk-weighted assets of some £400bn ($640bn), earnings of about £3bn and core tier-one capital of about £40bn. That implies a return on equity of about 7.5% and a core Tier 1 capital ratio of 10%.