The UK government on Tuesday doubled its bet on bailing out Britain’s two part-nationalised banks - RBS and Lloyds - adding up to £37bn of new money to the same sum it injected a year ago. The latest bail-out makes RBS by far the world’s biggest government rescue, taking as much as £53.5bn of state money, compared with the $45bn (£27.4bn) the US put into Citigroup. Lloyds, in contrast, sought to emphasise its commercial viability, launching a £13.5bn rights issue to which the government will contribute £5.9bn in line with its 43.5% stake.