My Mercury Prize torment

The Independent's Alexia Loundras is a judge on the panel of the annual music award. It's like pulling teeth, she says

I am a wonker. Seriously, I am. As an esteemed music monthly recently put it, the Nationwide Mercury Prize, far from being a prestigious music award, is in fact "a bewildering wonk-fest". And as one of the prize's ten judges for the past two years, that surely makes me a wonker. Or, at the very least, a wonky.

Like all panel-judged arts prizes, the Mercury Prize has a habit of working people into a tizz. Picking the album of the year is certainly a challenge: it is hard enough getting a pub-table of mates to agree - never mind earn the blessing of a pop-savvy nation and its critical media. But then the Mercury is not a popularity contest. Its aim is to draw attention to the 12 best albums released by UK and Irish-born artists in one year. And then, honour the top dog at a dazzling, televised shindig.

Judging begins six weeks before the shortlist is announced, when a courier struggles to your door with boxes packed full of CDs. Initially it looks like thousands, maybe even millions, yet they want to know your favourites in a month. Closer inspection reveals there are more like 200 cross-genre albums. But even that means life over the next 30 days revolves around the CD player, a pair of headphones and a notebook.

At first, having to pit so many different styles of music against each other feels a bit like being told you're a judge for Crufts then being presented with two dogs, a cat, an antelope and two tortoises. But it's amazing how the cream really does magically - and mercifully - rise to the top. Album sales and critical acclaim count for nothing.Quite simply, the judges vote for their favourite albums for the sole reason that they really, passionately like them. At least I do.

Still, the endless listening process is a bit like trying to find a diamond-tipped record needle in a haystack. After wading through 50 mediocre albums by everyone from two-bit gospel artists to deluded pop-acts, it becomes hard to remember what good even sounds like. But just when you feel like tightening the headphone chord around your neck, you are rewarded by the euphoric discovery of a glimmering gem in a desert of shiny plastic.

Each judge chooses their 20 favourite albums, then the votes are collated and of the 20-odd albums chosen, most make it onto the longlist. After a few days mulling it , over the first judging session focusses on each album's strengths. Over tea and posh biscuits, we take every record in turn and try to convince each other how brilliant and deserving of a nomination our favourites are - making for a very passionate but rather strange sort of debate. Every album is so pumped up with genuine praise, it seems as though each one of them could rival the all-time classics. A roomful of American sales reps on ecstasy couldn't be more positive. But the convivial atmosphere doesn't last long, because at the end of the meeting, each judge effectively votes albums out as they pick their ideal 12-strong shortlist in a secret ballot, and the 12 most popular albums make the final shortlist.

After the shortlist is announced, that's it for almost two months - apart from infuriating partners and neighbours by playing the nominated albums until every lyric, melody and seemingly inconsequential chord change are firmly fixed to memory. The next time we'll meet will be the afternoon of the awards ceremony. As the BBC's television crews set up cameras in the Grosvenor House Hotel's ballroom, the judges will reconvene for more tea and even posher biscuits. But instead of the chirpy optimism of the first judging session, we'll be armed with our own private battle plans that will help decide which of the 12 acts will win 2005's Nationwide Mercury Prize.

The first few hours of this final meeting are about elimination. If enough judges don't actively think an album should win the prize, it's game over for them. In fact, by the time the judges watch the shortlisted acts perform, many will be out of the running. Around us, industry bigwigs will be guzzling wine, though the plentiful free bottles on the judges' table will remain untouched for fear of dulling the faculties. After the first half of the show, the judges will be escorted back to their meeting room for dinner. While other guests tuck into their three-course meals, we must decide upon a winner and unless chronic indigestion is your idea of postprandial entertainment, eating is out of the question. Like Newsnight Review crossed with Trisha, this final stage of the judging can get vicious. As one judge fervently professes the greatness of an album, another will point out its manifest failings. Polite discussion dissolves into furious argument. The Mercury Prize is a big deal for the music industry, and, as a judge, you can't help but feel an enormous weight of responsibility to pick the right winner. One judge last year said the stress of those final hours was so extreme that he never wanted to do it again (and the pained look on his face proved he wasn't joking).

After about two hours of fiery debate, with all but the most popular albums eliminated, a final show of hands determines who walks away with the prize. And there is no way of knowing in advance who it will be. The Mercury has a history of throwing curve balls; from picking M People's Elegant Slumming over Blur's Parklife in 1994, to overlooking Radiohead's OK Computer in 1997 in favour of New Forms by Roni Size/Reprazent. You'd be amazed which middling album came second to Franz Ferdinand last year.

This year's race feels more open than most. I still can't decide which of the 12 albums should win. Only two things are certain: the winner of this year's Nationwide Mercury Prize will only finally be decided around five minutes before Jools Holland opens that sealed envelope. And after that, out of elation, disappointment or just sheer nervous exhaustion, the judges will finally crack open those bottles of wine.

The Mercury Music Prize is announced on Tuesday; the ceremony will be on BBC4