Although analysts and eurozone officials consider the prospect of the euro being dropped to be far-fetched at best, the mere fact that it is a subject of discussion makes leaders shudder.

Italian Social Affairs Minister Roberto Maroni shifted the focus of the growing crisis on the euro, one of the biggest European integration projects undertaken so far, by calling for his country to temporarily re-adopt the lira.

Maroni, who is a member of the Northern League party, told the newspaper La Repubblica: “Would it not be better to return temporarily to a system of double circulation.” The comment put EU monetary affairs commissioner Joaquin Almunia on the defensive, saying in Madrid: “I think that no one will be able to call into question an achievement that cost us so much to reach and which has brought us so many advantages.”

But although Almunia’s spokeswoman in Brussels Amelia Torres dismissed Maroni’s comment as a “flight of fancy” and insisted that "the euro is forever”, currency markets decided the mere mention of a break-up of the eurozone was reason to sell the unit lower.

The single European currency dropped to 1.2220 dollars in early European trading, from 1.2309 just before dealers began reacting to Maroni’s comments in the Italian newspaper La Repubblica. But it later recovered. The EU’s Luxembourg presidency acknowledged that the political uncertainty sparked by the constitutional crisis was weighing on the euro in the market. Luxembourg Prime Minister Jean-Claude Juncker said, “The fall in the euro is the result of insecurity linked to the European project”.

“We risk (seeing) the euro moving towards rates that do not reflect the economic reality,” he warned.

The growing EU political crisis this week has been taking its toll on European monetary union, until recently seen as one of the most successful attempts at European integration. On Wednesday Germany’s Bundesbank and finance ministry were forced on the defensive to insist they supported the euro following a report that the ministry blamed the currency for the country’s weak growth.

Although analysts considered Maroni’s comment to be a case of political opportunism, given that it was made by a member of a party hostile to the EU, they warned that some politicians were likely to voice further doubts about the euro.

“I do not expect any official initiative in the direction suggested by Mr. Maroni, but there is clearly a possibility of additional outbursts by other politicians trying to gain politically from the current anti-Europe wave,” said Bank of America economist Lorenzo Codogno.

Even though the collapse of the euro is a “science-fiction scenario”, as Belgium central bank governor Guy Quaden put it, serious concerns are growing about how to orchestrate economic policy for the 12-nation eurozone amid widening divergence in economic growth rates between some of its biggest economies.

Recent data have suggested that Germany, the eurozone’s most sluggish economy in recent years, is beginning to see growth pick up while Italy has slumped into recession.

While the ECB has insisted that its interest rates are at "appropriate” levels despite diverging growth rates, Juncker has called for a special investigation by the European Commission into the diverging fortunes of eurozone economies.