What goes up must come down, but the important question is when. Could it really be true that the age of the Spice Girls has passed as suddenly as it emerged?

It was a bad week for Gary Glitter. Arrested after child pornography was allegedly found on his computer he now faces being dropped from the new Spice Girls movie Spice World due to open on Boxing Day.

You could almost hear the girls groan - the controversy was also something they could do without. Where once the Girls could do no wrong, now they can do no right. They sack their Svengali Spice, manager Simon Fuller, they get booed off stage in Spain. Shares in EMI, the parent label of Virgin on which the Spice Girls record, fall, with dealers claiming the decline was a direct result of fears for the group's future. Their new movie is said to be so bad that one foreign journalist said, "You'd have needed a cattle prod to keep me awake during that rubbish."

Newspapers which had previously filled the pages with adulatory copy now urge the girls to split, carry anti-Spice jokes and have even conducted polls to find out who the most unpopular Spice was (Geri). The Mirror even ran a "wannaboo" telephone line (ho ho) which readers could ring to listen to the jeers hurled at the girls in Spain.

Bookmakers have started to take odds on Spice Girls to split and who would be the first Solo Spice to have a hit single (at present the favourite is Sporty Spice, who industry sources say has the best singing voice and enough charisma to carry off a solo career; Posh and Baby apparently aren't thought to have much of a chance).

Yet days earlier they were on the front page of every newspaper, flanked by the Prince of Wales and Nelson Mandela - or Princely and Presidential Spice as they were dubbed. Mandela said of Girl Power: "It's ... to be acknowledged - it's a fact." Prince Charles said encountering the Spice Girls was the second greatest moment of his life. (Asked what had been the greatest, he replied: "The first time I met them.")

However successful the meeting was, spookily, it was immediately after it that things began to go wrong. Yesterday they had to quash rumours that Ginger Spice - Geri Halliwell, who led the rebellion against Fuller - is to take over as the group's manager and to reject suggestions that the band might break up. Scary Spice Mel B said: "The Spice Girls are stronger and more positive than ever. We are really excited about the future."

They also said British press coverage of the last week's events was "unfair". Mel B told listeners to Radio 1: "It was only the British press who have made such a big deal about everything. We feel we have done a lot of good for this country. We have spread a lot of positive vibes and its a shame that where we come from, they haven't supported us."

Well, say the media observers, the girls did well but they started to believe their own hype. They got too big for their boots. They were a pop group for goodness' sake and they were never going to be around for ever. They should just go quietly.

Of course, said others, it's ridiculous that we should be talking about the Spice Girls at all. But the Spice Girls were different from other groups that had gone before; their steep rise and equally precipitous fall are of our time. And, at the end of the day, it all comes down to a brilliant branded product.

Ginger, Posh, Scary, Sporty and Baby defined themselves in individual ways to appeal to the aspirations of young girls and the fantasies of (not-so-young) boys. This was a clever device, which gave headline writers endless excuses to make dreadful puns and quickly defined them in a way teen bands had never been able to do before. Can anyone quite remember what Howard Donald or Jason Orange symbolised in Take That? Or would you want to?

It was a struggle - one media observer says that in the beginning the Spice Girls "couldn't get themselves arrested by the teen press". It began to change after they took out an "advertorial" in one of the magazines in which they introduced themselves.

Which brings us to the second thing about the Spices: Girl Power. It's so easy to sneer at the five's rather stumbling definitions of what Girl Power is about ("We are five individuals who do not have to be the same," said Mel B. "You can start your own business and believe in yourself. But you must help your sisters," added Geri Spice). But Girl Power managed to tap in to a now well-documented growth in confidence among young women. And at least they had a philosophy - anyone quite sure of what Boyzone believes in? Or Eternal? Or the Backstreet Boys?

Look back at less than a year, when Simon Sebag Montefiore interviewed the Spice Girls for the Spectator. Everyone chortled at the time at Geri claiming Baroness Thatcher as the first Spice, and saying that she considered standing in Kensington and Chelsea constituency after the fall of Nicholas Scott. It is hard to imagine Eighties success stories such as Duran Duran or Wham! willing to talk about political matters (George Michael saved such things until he was past the putting-shuttlecocks-down-his-shorts sort of age).

But as with any successful concept you have to be careful of how it is perceived. Weeks ago the magazine Marketing Week warned that the Spices were in danger of overkill - besides the Pepsi deal there is a link-up with Walkers crisps, an Impulse Spice range of scents, a tie-up with Chupa Chups lollipops, a Polaroid SpiceCam and a BT advertising campaign planned to run before Christmas. Research showed that the Spice Girls were endorsing so many different products that consumers were failing to keep track of the actual brands. And more than that: they were in danger of associating themselves with the wrong products. After all, a band which are huge in America, have sold 19 million records to date, and are due to see their movie open in a couple of months, to be endorsing Chupa Chups lollipops is - well - a bit naff.

While media observers rushed to damn the girls for their decision to sack Fuller, it was their ex-manager who had been destroying their credibility. Everyone of course expected that the girls would never last forever, but such naked determination to grab the cash by munching crisps, pulling crackers or choosing pizza toppings took the edge off Girl Power philosophy.

As the doom-meisters step in, one should remember that Simon Fuller did not create the Spice Girls, he only brought them to prominence - they had previously had another manager. And before everyone starts mourning Svengali Spice, may be getting rid of him means that in time the Girls could recover their image. Certainly Virgin are now stepping in, insisting that music will be more of a priority. A few more singles and a few less lollipops could help them regain their streetcred.

If the Spice Girls never put on a platform boot again, they will still be multi-millionairesses. But to write off the Spice Girls so early would be foolish. While first week album sales of 200,000 - less than bands such as Oasis and the Verve -may be disappointing, their last album sold slowly as well, and chances are that their teeny fans will all request Spice World for Christmas. And probably demand to go to the movie on Boxing Day as well. There's a world tour to come yet, and no doubt more Girl Power slogans. As long as they stay away from politicians. Or Princes.