London briefing/Chris Johns: Britain's eurosceptics have tended to be portrayed as grey men in suits, often in the mould of a Colonel Blimp type character, with no arguments to back their "keep the pound" stance other than pure jingoism. Indeed, there is more than a hint of truth to this description.

That being so, more thoughtful sceptics have tended to keep their heads down, fearful that they may be seen in a similar light.

Few of us want to be identified with the lunatic fringe of the Conservative Party. Some of us have even wondered whether we could, in all conscience, vote the same way as the jingoists in any euro referendum.

If we are to be judged by the company we keep, perhaps the time has come to join the opposition.

Happily, we can now banish these worries. Several things have happened over the last few weeks to prompt a growing realisation among the thoughtful sceptics that they have won the argument - without really trying.

The nutters were right, albeit for the wrong reasons. Tony Blair might still call his referendum - although this is becoming less and less likely - but we can vote no without feeling guilty. It is the only sensible thing to do.

The Swedish referendum result has been important, but has not been the only factor. That Sweden was able to have a sensible and thorough debate - although not without its own lunatic fringe - helped many people realise that the arguments for and against the euro have suddenly become very clear indeed. Sweden's eurosceptics were not dominated by ageing political has-beens; young people seemed very comfortable in voting no.

The euro debate has been conducted in a fog of jargon, half-truths and a dim awareness that Europe's troubled history has got something to do with it. Somewhere along the line, for all sorts of strange reasons, it became politically correct to support the euro project, no matter what the evidence or facts might say. In most European countries if you say anything rude about the euro, vilification always follows. The only time I ever get outright hate mail is when I say anything vaguely critical of things European in this column.

Britain's eurosceptics have suddenly realised that the euro isn't working. The existence of the euro has actually damaged each and every one of the economies participating in it. Britain's eurosceptics have suddenly realised that the Bank of England is operating monetary policy in a far superior way compared to the European Central Bank.

Europe sees nothing wrong in giving its 20 million cows half a billion euros a year in subsidies. Britain's eurosceptics can see the connection between the largest policy success in Europe's history - the Common Agricultural Policy - the collapse in the Doha world trade talks and Third World impoverishment.

For the euro enthusiasts all of this is irrelevant. The euro was always a political project and its existence reflects a massive political success story that dwarfs the trivial economic consequences. This is where the eurosceptics have had their "Eureka moment".

If the existence of the euro is all that Europe can aspire to, it reveals the emptiness of the European project. This is why Europe and America are moving so far apart: Europeans despise the beliefs of Americans; America despises Europe's belief in nothing. Britain is sick of its European partners simply adopting an anti-American stance in everything that they do. The world is a more complicated place than that.

Hence, thoughtful eurosceptics suddenly find themselves - to their own surprise - winning the debate. The case for the prosecution is overwhelming. The director of the Britain in Europe campaign - a creation of Tony Blair's - gave up the ghost last week. His resignation signalled a quiet acceptance that the game is up.

The response? We are told that to join is inevitable because life outside would be intolerable. Dark threats are heard about the consequences of staying outside. Brussels bureaucrats mutter about the implications of choosing to be excluded. From what, we might ask. As time goes by, this and similar negative arguments - never anything positive - are revealed to be simply wrong. Life outside is perfectly pleasant, thank you. The world has not ended because we stayed out. The UK economy has continued to grow as the euro zone slipped into recession.

Europe needs to figure out what it is for. To be fair, the new constitution was an attempt to provide an appropriate vision but I defy anybody to read the draft document and come away any the wiser. There is a real malaise at the heart of Europe. If economic goals are irrelevant, what is Europe trying to achieve? Answers, not necessarily on a postcard, would be much appreciated.