Bob Diamond, president of Barclays, has raised the stakes in the battle for control of ABN Amro by challenging claims that Royal Bank of Scotland would be able to extract more value from the Dutch lender’s investment banking operations.

In an interview with the Financial Times, Mr Diamond, who oversees Barclays’ fast-growing investment banking, investment management and private banking operations, argued that the British bank was better qualified than the RBS-led consortium to enhance the value of ABN Amro.