'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 now revealed the extent of the Government’s concern, saying that Britain is now planning on the basis that a euro collapse is now just a matter of time. “It’s in our interests that they keep playing for time because that gives us more time to prepare,” the minister told the Daily Telegraph.'

Read more: Prepare for Riots in Euro Collapse, Foreign Office Warns