British embassies in the eurozone have been told to draw up plans to help British expats through the collapse of the single currency, amid new fears for Italy and Spain. As the Italian government struggled to borrow and Spain considered seeking an international bail-out, British ministers privately warned that the break-up of the euro, once almost unthinkable, is now increasingly plausible. Diplomats are preparing to help Britons abroad through a banking collapse and even riots arising from the debt crisis. The Treasury confirmed earlier this month that contingency planning for a collapse is now under way. A senior minister has...