The British government blocked Royal Bank of Scotland from paying some staff bonuses worth twice their salaries to head off a public outcry, it emerged on Tuesday.Treasury officials intervened after the UK Financial Investments body, which oversees state holdings in banks such as RBS and Lloyds Banking Group, recommended that RBS should be allowed to pay such bonuses to help it attract and keep top staff, according to reports.The Treasury subsequently told RBS it could only pay staff bonuses equal to their basic salaries.