Tony, are you coming on the euro trip or not?

Ground Floor The euro was always a political rather than a financial concept. It was part of the grand plan of linking ourselves together for the common good of a European unit (a federal unit, although nobody wants to say that out loud).

A single currency for a group of states that have different cultural, economic and political backgrounds was never going to be easy.

It's akin to a group of friends with wildly different interests deciding to go on holiday together because they think they'll get a better deal that way. There's lots of bickering about the destination and the best time to travel. Weeks are spent poring over locations and arguing about what represents a good deal. Some decide to opt out.

When the others arrive at the final destination the differences are laid out for all to see, but in order to have a good time they have to bite their tongues and get on with it; even though there is sotto voce grumbling about people not replacing what they've taken out of the fridge or doing their stint at washing up.

Afterwards, when they come home and look at the photos, they remember the good parts of the holiday with enthusiasm and dismiss the difficulties.

Economically, nobody would have come up with the euro as a viable proposition for another 100 years or so and probably not even then. If every country who adopted the euro in January 2000 had waited to fulfil five economic tests, it wouldn't have happened at all. There are still too many differences within the euro zone to make it anything other than a difficult alliance. But politically, like our friends going on holiday, there's a case for making it work.

As far as Britain is concerned, however, the political will still isn't strong enough despite some masterly spinning in the wake of Gordon Brown's latest "yes, but not yet" pronouncement.

If they gauge political will solely by whether or not the population wants to join the euro, it'll never be strong enough.

I guess the Irish psyche was never too bound up with the notion of the punt, but the British have invested a lot of self-worth in the pound and it's not something that they're willing to give up in a hurry.

The reaction would probably be similar if a sporting alliance of England, Scotland, Wales and Northern Ireland was suggested to replace each individual soccer team. Nobody would be keen to give up what they've got simply to be the British team. It wouldn't mean the same and some of the passion would go.

So, despite Tony Blair's desperate attempts to drag them into thinking that fog in the channel doesn't mean that the continent is cut off, he's got his work cut out for him. And they'll only meet the economic tests when and if the political test has been met first.

One of the most contentious economic elements (leaving aside the "is it good for the economy?") is whether or not the British economy and those of Europe are converging.

The problem about the convergence theory is that, given how dreadfully the euro zone is currently performing, any further economic stumbling from Britain would be enough to help Labour lose both a referendum on joining the euro and the next election. And that's without any of the other brickbats that can and will be thrown at Blair's government in the coming years.

Yet, in another way, convergence is the easiest of all measures to meet. Convergence is about trends, not about actual numbers. And there isn't a major economy in the world that hasn't slumped in the past couple of years.

None of us is doing particularly well. Industry blames a general decline in consumption and overseas orders. The Americans gripe at the Europeans for not buying enough, the Europeans look anxiously at the US to bale them out of the economic doldrums and everyone despairs of Japan. We are already a global economy.

Very few countries can buck the world trend. Some may perform a bit above the average, some may perform below. But on the issue of convergence, the world is one big market and we're all at sea in it.

Politically, Europeans would be happy to see the Brits come on board because it strengthens the concept of a one-stop-shop Europe. Economically, they'd be welcome too - it would make trade with Britain much easier and have the potential to help both mainland Europe and Britain overcome difficulties in other markets.

Many British politicians and business people think that the euro zone is too inward looking and they're probably right. Traditionally, Britain has looked to the US as one of its major overseas markets. But greater participation in Europe would have benefits too. Having Britain onside in Europe can improve both sides of the trading equation.

Just because something that you'd like to happen in an organisation isn't happening, it doesn't mean that it never will. Nor does it mean that you can't be an influence of change. And though Europe might spend too much time navel gazing, most businesses are prepared to look at other markets when their own aren't delivering what they want.

At the moment, though, it's like waiting for the final couple of friends to make up their minds about the foreign holiday. They've got the glossy brochures and they like the look of the villa under consideration, but they're simply not convinced that there isn't a better deal to be got somewhere else. They're still not sure where, and whether someone else will invite them along. But they're holding out just in case.