Ministers have been urged by an influential committee to draw up a plan of action to help the country cope in the event of a eurozone collapse.
A joint committee of MPs and peers who are part of the UK's National Security Strategy (NSS) said ministers needed to prepare plans to deal with a break-up of the eurozone "as a matter of urgency", despite recent signs the crisis on the continent is coming under control.
According to the BBC, the NSS said the full or partial collapse of the single currency was "plausible".
It said a collapse could lead to political unrest and a rise in the number of economic migrants trying to enter the UK, and urged ministers to come up with some solutions to such outcomes.
"International economic problems could lead to our allies having to make considerable cuts to their defence spending, and to an increase in economic migrants between EU member states, and to domestic social or political unrest," it said.
Committee chairman and former foreign secretary Margaret Beckett said: "We need a public debate on the sort of country we want the UK to be in future and whether our ambitions are realistic, given how much we are prepared to spend."
The committee, whose members include ex-MI5 director general Baroness Manningham-Buller, said economic instability could also leave the UK "unable to defend itself".
Much has been made of the chances of a eurozone collapse, with fears mounting Germany may not keep picking up the tab for other nations who overspend or lose control of their fiscal policies.
However, leaders across the continent - and in particular major nations such as Germany and France - have publicly backed the single currency and re-stated their commitment to it.
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