In an interview with the Financial Times, veteran boss Oswald Grubel hit out at the British government for its handling of the Project Merlin agreement, suggesting politicians had done little to play down anti-banker rhetoric.
"The government is so quiet about [the City]. Only behind closed doors do they pay lip service to wanting to keep the City," he commented. "If it is abandoned by the government one day, God help you."
Mr Grubel also criticised Swiss authorities, claiming that a growing number of lenders are likely to relocate to the US and Asia in the next few years as a result of Switzerland's increased capital requirements.
Earlier this week, Royal Bank of Scotland Asia chief John McCormick told Reuters' The Future Face of Finance event that returns on equity would struggle to reach previous highs because of capital rules.
By Gary Cooper