Tonight the Eurovision Song Contest returns, with its booms and its bangs, its oompahs and its la-las, its spangly jump-suits and its nul points for Norway. As the pan-European vocal chords wobble into action, sharing a single currency of the tune-free and the forgettable, an expectant audience will be settling in to enjoy the long evening.

In student bars the beers will be stockpiled in anticipation; groups of smart, metropolitan gay men will be cracking open the Campari; sophisticated dinner parties will break for a laugh at the voting: everywhere you go this weekend, kitsch enthusiasts will be preparing for a three-hour wallow in this marathon of the naff.

And the pleasure of these irony lovers will be edged up a notch or two by a cunning piece of casting by the BBC which, because the British entry won it last year, is hosting the show this time around. To present it alongside Terry Wogan - our veteran guide and a man with highly-developed sarcasm monitors well attuned to the event - the BBC has invited Ulrika Jonsson. And the former breakfast television weather woman, presenter of Gladiators and a collaborator on Shooting Stars, is already limbering up her humour muscles for the occasion.

"I'm warning Terry Wogan here and now," she says, as she sits in the swanky basement cafe of a swanky designer clothes shop in London's swanky Bond Street, sipping tea from a less than swanky dirty cup. "He takes the piss out of me on May 9th and he loses a kidney."

It is a particularly skilful piece of recruitment to match the programme, which has been reinvented in the past five years as cult viewing, with a woman who has so skilfully surfed the wave of irony engulfing British television this past decade.

For those who get the Ulrika joke, she is the perfect light entertainment figure for the modern age. Her skills are much more than simply being at ease with a camera that is infatuated with her. In the curl of her lip and in the look in her eye, there is a knowing quality that suggests there is plenty going on behind the contractually-required smile.

This is a woman, her television presence implies, who wants you to know she isn't taking any of this seriously: the programme, the situation, herself. That's why she was hired for Eurovision, wasn't it, to take the piss?

"I wouldn't be able to answer that," she says diplomatically, as she stares disapprovingly at her soiled cup. "You'd have to ask whoever did the hiring.

"I don't think the BBC would try and take the piss anyway. I mean if you had any idea how seriously they take this, you'd be amazed. Besides, I think it's been a culty thing for a while, I don't think I would make a difference to that. There's been a lot of student parties watching it for years."

Precisely. Ulrika is, after all, a student hero, the ladette whose party trick is downing a pint of beer in one. Not something the Eurovision host has traditionally done between introducing entries from Malta and Israel.

"Anything could happen on Saturday, it is a live show, tune in," she says. "It is real beer, by the way, but most of it goes down my top. So it's never really a whole pint I drink. Most of it rests in my bosom."

For someone only just in her thirties, Ulrika - she is one of those light-ents figures who doesn't need a surname anymore - has been around a long time. She is a creature entirely of television, with no career prior to this in acting, comedy, journalism or sport. Not that she had never harboured ambitions for a life in telly, she says.

After coming here from Sweden as a 12year-old when her mother remarried an Englishman, she set her heart on becoming an actress. She had simply taken a job as programme controller Bruce Gyngell's secretary at TV-am in her year off before going to Goldsmiths' College, London, to take a degree in French and drama.

During a debilitating strike at the company, when it was all hands to the pump, she was offered a screen test to read the weather.

"I blew it, I was crap, incredibly nervous. Oddly, though, preparing for that audition, I'd really got into the weather. I studied it and loved it. I mean, I love the weather. Partly as a result of all the study, I landed a job with a satellite weather channel broadcasting across Scandinavia, so I left TV-am."

After a few months forecasting for the fjords she bumped into her former boss one day and, hearing what she was up to, he invited her back to do some relief shifts at TV-am. Gyngell liked this stand-in so much that she stayed.

"Bruce liked eyes and teeth and sunshine and bright colours, so I fitted the bill," she says. "I went with the flow, I'd given up the idea of French and drama and instead for 31/2 years I did the weather on breakfast telly.

"I tell you, mornings are shit. But I've never got the weather out of my system. People sometimes say to me, `What's the weather like with you?' And I say, `It's about 15 degrees centigrade, that's 59 fahrenheit, there's 60 per cent cloud cover and the chances of precipitation are medium to high'. And they say, `We were only asking to be polite.' "

To her good fortune, she had happened upon a great time to be in weather. Taking a lead from America, TV-am was the first in this country to promote this backwater of broadcasting as something vital and vibrant. Because she was Swedish and good-looking, the tabloids couldn't get enough of Ulrika.

WITH such attention came job offers. In 1992 she was given the chance by LWT to anchor a new Saturday prime time show called Gladiators. "This peculiar offer came in for presenting a programme involving massive body-building people bashing the hell out of each other with giant cotton buds. And I thought: I'm not sure. You know, it's great to be on something new, but if it's a flop, it's not so great."

Gladiators, though, was a ratings success, partly because of Ulrika's confident, brisk handling of the contestants. Seeing those musclemen mother-henned around by the woman they towered over, there was something appealingly schoolmarmish about her performance.

"Is this a sexual fantasy of yours?" she asks when the point is put to her.

Ah, well, er. Perhaps what is interesting to know is if this is a true reflection of her character? "I think mainly because I've been doing it for years, I am kind of confident with the programme."

She doesn't take it seriously, though, does she? `I appreciate the serious efforts of the contenders,' she says, after a long pause to weigh up the most diplomatic choice of words. "Look, the contenders I take seriously. But when some man called Wolf comes up and growls in my face, I really can't pretend that this is a sane way to earn a living."

Or someone called Hunter. When, a few years into the Gladiators run, Ulrika started to indulge in private gladiatorial combat with a member of the cast, it created a new dimension for the show. There was a frisson, a sexual tension, and the ratings, as it were, shot up. After Hunter there was a supposed dalliance with comedian Vic Reeves.

Another consequence of her fame is an image that, she maintains, is entirely inaccurate.

But isn't she partially responsible for the image? For instance, if she was keen to remain a private person, or indeed to challenge the time-worn linkage between blonde and dumb, was it a wise decision to allow herself to be photographed by Loaded magazine trussed up in bondage gear while bragging about her lack of nether garments?

"I suppose I've helped to create the image I have. But I'm not sure how I'm supposed to live my life. I just do what I enjoy doing. Those who know me know what I'm really like and whatever intelligence I have, and I suppose everyone else will have to live with this illusion."

This is the dilemma of her strange calling. In order to be hired, to work, she needs to be in the public eye, so she cannot hide from publicity. Plus she is a naturally likeable, engaging person, so she prefers to speak to a paper in a friendly manner rather than be confrontational.

And because she has a sense of mischief and doesn't think too long and hard about the consequences of what she says and does, things can spin out of her control. The comment she made to Loaded about a knickerless condition was, she maintains, a joke.

For some commentators, though, the image of Ulrika is the embodiment of cultural decline in Britain. Ulrika is, according to those employed to say such things, the epitome of the dumbing down of British television.

"Dumbing down, what does that mean exactly?" she says, holding back a knowing smile just long enough for her interviewer to think for a moment that she is being serious.

"But you see, they're wrong. I don't want to make television look stupid, I love it too much. Ridiculous, yes. But stupid? No. There is a difference."