91Èȱ¬

The reason it matters for British swimming is that it's even taking place.

"The British team is now stronger than it's ever been. This could never have happened a few years ago," Olympic bronze medallist turned 91Èȱ¬ commentator Steve Parry told me.

"The British team is very strong indeed, particularly the girls. You've got , , - these are all big world names. They'll walk into this arena, it's going to be a charged atmosphere, and I wouldn't bet against some extremely fast swimming this weekend."

Adlington agrees. "This is definitely a good thing. It shows swimming is moving forward and our profile has been raised a lot," said the , a woman whose success in Bejing both crowned the first stage of British swimming's resurgence and kick-started a second push for greater glory.

"We're a good nation at swimming now," she added. "Before, the US would have gone, 'Well, there's no point', but now they think we're pretty good and they're probably worried about us as well. I hope they are."

Britain has no history of international head-to-head competitions like this, but the US holds them at regular intervals, with Australia the usual opponents.

Yet the achievement of attracting the US and staging this event has been eclipsed by a bigger issue before the swimmers even take to the pool: not who will win or how individuals perform, nor even the arrival of swimming machine Phelps, but .

That's because this is the last chance they will have to wear the 2009 edition swimsuits that have caused such controversy.

Made out of special materials which appear to offer a boost in speed that is otherwise beyond reach - hence the unprecedented number of broken records at - these suits , swimming's governing body.

But the ruling doesn't kick in until 1 January, so the 2009 suits are legal for . Some swimmers, like Phelps, say they will use the 2010 model in Manchester, which is slower but will be legal come January, on principle. Others, like Halsall, say they will milk the 2009 suits for all they are worth one last time, in pursuit of victory.

This means Duel in the Pool could be livened up by some freak results. For example, if Phelps wears a 2010 suit but his European rivals opt for hi-tech 2009 versions, he is in real danger of losing. Great Britain's , who will go up against Phelps, says his coach has specifically advised him to wear a 2009 suit with that in mind.

Whether you think that's a legitimate method of winning is another matter. And while the swimmers here will enjoy themselves more than they ever would at an Olympics or World Championships, they still want to win.

"I'm a bit more chilled out because it's only a two-day competition and not a major meet, but at the same time I want the most points I can get," is the view of Adlington, while GB team-mate Spofforth, the 100m backstroke world champion who trains in America, is keen to show her training partners who's boss.

"Beating the US would be super-special and will play in the back of my mind all weekend," she said. "Coming fourth in the 200m backstroke at the Worlds was a big inspiration to me. I never want to come fourth again. That name, 'Spof-fourth', has travelled with me." To motivate her, she now keeps a photo of the three women who beat her as the background on her computer desktop.

"It's fun," fellow Briton Halsall admitted to me, "and it's a bit different because as British swimmers we don't get much chance to take part in duel meets. But most of the British team are quite competitive and want to win anyway. Having the best people in the world on our doorstep in Manchester makes it more exciting and really raises the profile of swimming."

And that brings us on to the sheer spectacle. Manchester held the last year, but even that didn't get the treatment and build-up Duel in the Pool has received. The finishing touches to the pool are being made as I write, with spotlights racing across the water, filling the arena, a big screen ready to display the points tally, and thousands of seats waiting to be filled. British swimmers rarely get a stage like this in front of their own fans.

"Manchester put on a great show for the 2008 World Short Course and that was my first real buzz of a home championships," said 50m backstroke world champion . "I was getting out of the pool with people chanting my name. I'd like to see that here - the Brits getting behind the European team - and I think that's what we're going to see. I love the lights and the music, it's more fun and more lively."

"It's going to be so noisy poolside," said another Brit, . "Everyone is going to be screaming their hearts out. It's good to get the crowd involved. It makes the atmosphere electric, and my family are going to be glued to the TV screen at home."

In record books and biographies years from now, will the events of the next two days feature much? Probably not, but that isn't the point. What the duel offers is some of the world's top swimmers putting on a show. There are no heats, just finals, so every swim counts. Swimmers earn five points for a win, three for second place and one for third, with seven-point bonuses for victory in the relays. Organisers want to see crowds - and swimmers - tense up as the points tallies mount on the big screen. It's an event made to raise the hairs on the back of your neck.

And who will come out on top? Most people here, if pressed, would say it's hard to see how Europe can snatch this. They are like Federica Pellegrini, Britta Steffen and Jo Jackson, whereas the only casualty in a US team packed with strength in depth is Ryan Lochte. But the European team haven't given up hope.

"The American team have brought their A game. They've brought everyone they took to Worlds, so it'll be a difficult ask for the European team," admitted Halsall. "But with the quality of swimmers we have now, we stand a good chance if we get stuck in and make the most of it. We've got a good group and I think we can ruffle some feathers."

Watch the live on 18 December - 1900-2100 GMT, 91Èȱ¬ Three and 19 December - 1345-1630 GMT, 91Èȱ¬ One. All the action is on the 91Èȱ¬ Sport website (UK only).