Is it goodbye from Julien?

The panic is over and Julien Macdonald is having a calm moment. He has tracked down the lost half of his collection to the customs office at East Midlands airport and it is due to turn up at any minute.

More of his collection is arriving at Stansted from Italy after midnight and he will stay up all night to ensure it gets to his west London studio safely. "I've spent the entire day screaming down the phone at delivery people for my clothes," he says, his soft Welsh lilt betraying a hint of weariness. "I was going mad. I've got half of the collection but not the half I want. I've got the jacket but not the skirt, some of the shoes but no belts. It's been a crazy day."

You get the sense that every day in the life of 31-year-old Julien Macdonald is pretty crazy. If he's not shouting at hapless couriers, he's zooming between Paris and London, or putting the final flourishes - most likely a ton of sequins - to a jaw-dropping gown for one of his A-list friends.

The preparations for his show tonight, at the old Saatchi gallery in St John's Wood, have taken weeks and his team have worked around the clock. Yesterday, he was still casting models ("We haven't confirmed them yet, but we'll be getting the best that life can offer"). Add to that his ready-to-wear and couture collections for Givenchy, where he is head designer, and the red-carpet dresses he is creating for the awards season and it's a wonder he has any spare time at all.

"I'm dressing Kylie for the Brits," he says. "If she goes. She's already changed her mind four times so I said, 'Do you want the dress or not because I've got a show to put on?'" (In the end, Kylie didn't turn up, the fickle minx, but happily Rachel Stevens wore a Julien Macdonald canary cut-out.)

With his high-octane glamour on the catwalk and his celebrity friends in the front row - Beyoncé will be there tonight - Macdonald is one of the biggest draws of the increasingly lacklustre London Fashion Week, but this could be the last time we see his sparkly, spangly creations in the capital. For, as Julien tells me, sounding resigned, he could be forced to show his next collection in Milan.

"London Fashion Week is still a great event," says Macdonald. "It has created the most exciting fashion designers and is renowned for young talent, but there just aren't the facilities to keep the top designers here. The Government needs to give the British fashion industry more funding. I'm the one who stayed but if I don't get the international press and buyers, I will show in Milan next season. It's a glamorous place and I'm a glamorous designer." Having lost John Galliano, Alexander McQueen, Hussein Chalayan and Stella McCartney, who all now show in Paris, it will be a huge blow to the British fashion industry if Macdonald goes.

A combination of the economic downturn and lack of organisation and funding means that the influential editors and buyers have stayed away since the halcyon days of Cool Britannia in the mid-Nineties, forcing British talent to go with them. It just didn't make business sense to put on a show - which can cost upwards of £20,000 - if none of the influential buyers was there.

This week there are 39 designers showing (last year there were 50) and it is thought that only 2,000 international journalists and buyers are in town. By contrast, Paris regularly lures 10,000. And none of the big glossy editors - Anna Wintour of US Vogue, or Glenda Bailey of Harper's Bazaar - have bothered to turn up.

For now, at least, Julien is the hottest ticket in town and tonight, we can expect as much glitz as ever. "The summer collection was very young, all about clubbing the night away. This time it's luxurious, it's Elizabeth Taylor and Sophia Loren in their heyday. There are tailored tweeds, leather, exotic feathers and animal prints - and that's just for day. For night, I've done spectacular, ultra-sexy spangly crystal dresses and full-length gowns."

In other words, Julien Macdonald, King of Bling, is doing what he does best. He is also using £10 million worth of diamonds and has had to take on extra security guards, not just for the gems but to keep the animal rights protesters at bay - this season, fur and exotic skins such as crocodile feature heavily (members of People for the Ethical Treatment of Animals stormed his catwalk last year).

The other big question is whether Macdonald will stay at Givenchy, the Parisian couture house which he has headed since March 2001. His appointment was controversial - critics didn't think he could fill the shoes of previous incumbents John Galliano and Alexander McQueen - and his collections haven't been well received. Last year, the fashion doyenne Suzy Menkes wrote: "Julien Macdonald was even more out of sync with everything going on in fashion." Another critic described his tailoring as "lumpen". At his couture show in Paris in January, only a few hand-picked fashion journalists were allowed in, fuelling rumours of damage limitation (it is still thought that the show last month was his last couture collection). But Macdonald, ever ebullient, isn't fazed.

"I try my hardest," he says. "It takes a long time to make a brand work and other people in my situation didn't get good reviews at the start either. It took Galliano years to make Dior work and it's the same with Marc Jacobs at Louis Vuitton. I didn't let the world's press in because there wasn't enough space."

Although it is widely expected that Givenchy will not renew Macdonald's contract when it runs out in April, he refutes rumours that he has already decided to leave.

"I haven't left," he says. "There has been a lot of gossip and no official statement. Put it like this, they're very happy with me. It's fashion gossip but I love it if people are talking about me. My contract is up for renewal but we're still in negotiations. I would like to stay at Givenchy, I think I've created something very special

there and I've managed to attract some famous, influential people to wear it. Liv Tyler would never have agreed to be the face of Givenchy if she didn't like the product."

Givenchy also refuses to be drawn. "Julien's contract ends soon but our collaboration with him may not end," says a spokesman. "He is doing the ready-to-wear collection in March and he is still our head designer." For now, at least, Macdonald is happy to divide his time between his mews house in Notting Hill and his apartment in the Place des Vosges. "Paris is an amazing place to work," he says. "The French are not the most creative of people but they are the most stylish."

Even if he does leave Givenchy, it won't be a blow to Macdonald's career. He would have more time to do what he enjoys the most - dressing the world's most glamorous women, most of whom have visited his small west London studio for fittings. "The amount of black limousines I've had outside is hysterical. My newsagent is in awe of me," he laughs. Clients who have now become friends range from Hollywood heavyweights Cate Blanchett (endearingly, he pronounces her surname "Blanchlett") and Liv Tyler to Kylie, Janet Jackson, Jennifer Lopez and Christina Aguilera, who is "tiny, smaller even than Kylie, it's amazing!".

British fans include Martine McCutcheon, Kelly Brook , Joely Richardson and Victoria Beckham. (A cobweb dress starts at £500, and can cost thousands.) His world now is a far cry from the decidedly unglamorous Merthyr Tydfil, where he grew up with his two sisters, mother and father, a former Aston Villa footballer who worked for the Hoover factory

When he was 16, he asked for a sewing machine and, following a textiles degree at the University of Brighton, did an MA at the Royal College of Art. It was there that Karl Lagerfeld spotted him and Macdonald began designing knitwear for Chanel. Macdonald launched his own label in 1997 and knew he had arrived when he turned on MTV one day to see Janet Jackson dressed head-to-toe in his clothes.

"Celebrities are the new supermodels," he says. "I turn down a lot more people who ask for clothes than I say yes to. I look for someone who will look great in my clothes and enjoy wearing them." He is excited about the Oscars but refuses to say who he will be dressing. Liv Tyler? "I would say she is a very strong contender," he says. "Or Kim Cattrall. I dress her quite a lot. What girl doesn't want to be like her? She's as sexy as a snake."

Pity the poor women Macdonald accosts in the street for not being glamorous. "I went up to a woman in a nylon tracksuit and said, 'I think you've made a mistake today'," he laughs. "She knew who I was and said, 'Thank you for telling me'. I don't think I offended her. Women should never leave the house without full lipstick, preferably bright red, and the highest heels they can manage. I hate flat shoes and I hate sportswear."

I tell him his comments will incur the wrath of the feminists but he doesn't care. "I create a dream," he says. "It's escapism. Most normal women don't want to be themselves, they want to be the glamorous celebrity they see on the red carpet. My clothes lift you out of reality and take you into another world."

The showmanship Macdonald brings to London will be sorely missed. As Laura Craik, the Evening Standard's fashion editor, says: "All designers get to the stage when they want to move their business up a notch and he will have experienced the level of efficiency of Paris, so it's not hard to see why he would want to leave London.

"It will be one extra defection and it looks bad if we can't hold onto him."