Ground Floor: Whenever I go to Belfast or London I remember, too late, that I've forgotten to bring any sterling with me. So there's the usual flap while I look around for a cash machine and persuade it to hand over the readies. And on the way home I always end up with a selection of low denomination notes and coins which I throw into a drawer and forget about; so that the next time I make the trip I go through the whole palaver again.

By contrast, when I head over to Spain next week I won't have to think about the money situation at all. I'll withdraw some cash, shove it in my purse, check that the credit cards are nestling in the right place and just go. For me, and anyone who travels throughout Europe, the euro is a convenience currency. Since the rejection of the EU constitutional treaty by the French and the Dutch its status is under threat.

There were always issues about the one-size-fits-all monetary policy which had to cover members of the European Union in the run-up to and after the adoption of the single currency. Ireland's runaway economic success is partly due to the fact that it wasn't choked off by the higher rates that the Government would most likely have introduced to slow down our love affair with spending.

The Irish, while complaining bitterly about the rip-off nature of prices post its introduction, nevertheless accepted the euro far more quickly than some of our partners. The British, of course, didn't accept it at all.

The Germans believed they were in control of it, realised very quickly that they weren't and began to think nostalgically of the days when the deutschmark was the king of European currencies.

But the Italians - well, they've starting to talk about abandoning it altogether. According to Roberto Maroni, the Italian welfare minister, the euro has been "inadequate in the face of the economic slowdown, the loss of competitiveness and the jobs crisis". Suddenly the economic malaise which has cloaked Europe over the last five years has found a cause in the single currency despite the fact that in itself it has not been to blame.

The rejection of the treaty was a rejection of the entire bureaucratic machine that runs Europe - whether enlarged or not - and a rejection of a political imperative that doesn't address the concerns of individual states.

There is a definite problem with the concept of a single currency and a plethora of nations at different stages of economic development.

The plan, of course, was that adherence to the Stability Pact would standardise the background for every member state so that one currency could fit all. But, as sectional interests abound, that's been virtually impossible and people are looking for someone or something to blame. They've rejected their leaders, now they're rejecting the currency. And it's all becoming horribly messy.

There is a crisis of confidence in Europe at the moment. Old Europe is caught in a nostalgia for the past and blaming the present on unrealistic plans for the future. Countries which put social issues ahead of economic growth (because previously they could afford generous welfare systems and still be competitive) are now finding themselves lagging behind on the world economic stage.

For as long as I can remember the German government was talking about labour and welfare reforms in order to make Germany competitive in the global marketplace again. These issues had nothing to do with the EU or the euro, but the demographic situation of the country itself and the change in the way the rest of the world had decided to do business.

But the Germans, like the French, are still floundering in the area of labour markets while eastern Europeans do their best to attract big business into their region and aren't hampered in their productivity by the kind of benefits that old Europe offers its workers.

There's a two-tier, two-speed Europe and a single currency. It was bound to cause problems as long as leaders talked about change but didn't actually make changes. Unfortunately very few people are comfortable with the sort of change that sees industry moving east towards cheaper countries in which to do business, while labour moves west to take advantage of better wages and social conditions.

The value of a currency reflects the views of the world marketplace on the economics of the country that uses it. There is no doubt that the world looks askance at a Europe which is heavy on bureaucracy and light on innovation. But Europe's problem is wider than that.

The reality is that a single currency all but requires a political union and the citizens of Europe most certainly don't want a political union. The United States of Europe may well be a dream in the minds of some of the people who roam the corridors of Brussels or Strasbourg but it's cutting no ice in the streets of Paris or Berlin.

Or indeed in Italy where the current economic malaise would traditionally have been dealt with by borrowing more and devaluing the lira, an option not open to them anymore.

The president of the ECB, Jean-Claude Trichet, came out in defence of the euro and said that talk of abandoning it was as likely as "California ditching the dollar" but he must be feeling under pressure all the same. The concept of the euro is not fatally flawed but it requires a commonality of purpose currently lacking.

Right now the market is pricing in economic mayhem in Italy. But it would have done that with or without a single currency. If the Italians weren't in the euro zone, their spread over German bonds would be more than the 23 basis points currently on offer. Borrowing would be expensive.

They'd still be in a mess. There's no easy road to economic progress.

There never was.