Nick Clegg has warned that the continued eurozone crisis could lead to a rise in political extremism and xenophobia in Europe.
In an interview with Der Spiegel ahead of a visit to Berlin this week, the Liberal Democrat leader hit out at a lack of leadership on the eurozone crisis, cautioning that there could be an increase in extremism unless it was addressed.
He said: "This cannot carry on, because the combination of economic insecurity and political paralysis, we know this from the history of our continent, is the ideal recipe for an increase in extremism and xenophobia."
The deputy prime minister added that arguments in the UK over whether the Britain should join the eurozone would be "like a small side show compared to the rise of political extremism" in the coming years.
It is a stark assessment from Clegg, who has been a long-term advocate of the European project.
"I, as a passionate Liberal and pro-European, think it would be a disaster if a lack of grip and a lack of a comprehensive solution were to lead to a push towards the extreme Right or the extreme Left," Clegg said.
He added: "If the eurozone does not come up with a comprehensive vision of its own future pretty soon - in three, four, five years time - we will have a whole range of nationalistic, extremist, xenophobic and populist movements increasing across Europe."
In October last year, German Chancellor Angela Merkel gave a similarly bleak assessment, warning that if the "euro fails, Europe fails".
In the interview, Clegg warned that Germany must do more than merely insist on austerity if the eurozone was to stabilise. He also admitted that the coalition may have been too "dogmatic" in its rhetoric on cutting spending.
"You have to have something which creates a fiscal accompaniment to monetary union," he said.
"Whilst I have a huge amount of sympathy with German taxpayers and German politicians who are reluctant, understandably because Germany is the paymaster of the European Union, to entertain these ideas, I fear that they are unavoidable.
"It is not sustainable to believe that the eurozone can thrive through fiscal discipline alone - it also has to, at some level, include an ability to either share debt or to deal with shocks in one part of the system or the other through fiscal transfers."
Clegg denied that the coalition parties were "austerity fanatics".
"Maybe our rhetoric has been too dogmatic in the early stages because we needed to persuade people it was necessary," he said.
Clegg insisted people should look at what the government had "actually done".
"Last autumn when I was told, when David Cameron was told, when George Osborne was told that the predictions of growth and the public finances in Britain were worse than we'd anticipated what we could have done was to cut more to meet our initial target in dealing with the structural deficit by the end of this parliament," he said.