Last year, after much speculation, the high priestess of 'yoof' television finally secured herself another BBC job. Whiston was appointed to pick up the pieces and devise a strategy to counter Channel 4's achievements. With shows such as The Big Breakfast, Don't Forget Your Toothbrush and The Word, Channel 4 has demonstrated there is more to ensnaring the under-25s - the so-called hard-to-reach generation - than the wobbly camera angles and eyeball-perforating graphics of the Street-Porter short-attention-span school.
'With a very small amount of airtime, Channel 4 has made a much bigger impact than the BBC in youth programmes,' Whiston admits. 'But I sense that a programme like The Word has run its course and taken things to the limit. Obviously they're searching for the next big thing - so are we.'
Whoever wins that battle, Whiston is unlikely to concede defeat without a fight to the finish. The Manchester-based programme department he has inherited from Street-Porter makes 270 hours of network television a year with a budget of around pounds 30m. After Pebble Mill in Birmingham, Manchester is the BBC's biggest regional production centre. A recent initiative to boost programme-making in the regions means that Whiston's budget could increase by a third in four years.
As head of youth and entertainment features, Whiston has an empire embracing such mainstream shows as BBC1's How Do They Do That? and That's Showbusiness, quizzes (Mastermind, The Travel Quiz and the new Jeremy Paxman- umpired University Challenge); documentaries (Great Railway Journeys) as well as youth programmes. But it is in the youth area that he is most determined to change things and where he faces the toughest competition - not only from Channel 4, but also from satellite television, which can provide dedicated rock and pop on MTV 24 hours a day.
Before Whiston's appointment, and with Street-Porter no longer around to oppose him, Michael Jackson, the BBC2 controller who succeeded Alan Yentob last spring, decided to introduce a more flexible approach to the scheduling of youth programmes.
DEF II, the twice-weekly early evening youth strand introduced by Street-Porter with a fanfare of hype in the late Eighties, has been abandoned. Out, too, are most of its shows, including the black music programme Dance Energy and Reportage, that uncomfortable mix of high-speed editing and actuality footage. The high-profile fly-on- the-wall documentary The Living Soap is another casualty of the new regime, but the acclaimed Rough Guide To The World, presented by Magenta De Vine and Rajan Datar, will return. In future, BBC2's only fixed slot for youth programmes will be early Monday evenings, and this position in the schedule is far from guaranteed.
It was felt that the predominant style of these programmes, the frantic pace and obligatory dance sound-tracks, was dated. The fact that they occupied fixed places in the schedule, and were shown at times when much of their target audience were either studying or out having a good time, was another burden.
Moreover, there was little evidence that they were particularly popular with the 16- to 24-year-olds they were designed for. Last year the BBC revealed that only 14 per cent of its viewers came from this magic age group and that as many over-65s were tuning in to programmes intended for their grandchildren. Critics claimed that Street-Porter's personal profile was higher than her shows' ratings.
'The truth is that youth audiences watch what everyone else watches,' Whiston says. 'They're heavy watchers of soaps and sitcoms, but actually quite shallow watchers of TV. They're too busy living their lives rather than watching them. They know where Moviewatch and The Word are. They don't need a huge sign saying 'It's For You-ooo . . .'
Ask teenagers what they watch regularly and they will almost certainly nominate Neighbours, The Word, comedy and 'anything with Chris Evans'. Nevertheless, Whiston denies any fundamental break with the past - or suggestions that Street-Porter's approach to her audience tended to sacrifice substance on the altar of style.
'What Janet achieved here is remarkable. She went from a couple of people in a room to what I'm inheriting, a pounds 30m business. The fact that I'm referred to as 'the new Janet Street-Porter' says a lot about her impact on the BBC.'
Whiston, 35, joined the BBC in 1983 as a general trainee after Oxford. He won his reputation at Television Centre in the music and arts department as a protege of Michael Jackson, working alongside him on The Late Show and scoring with such programmes as his Bafta award winning Naked Hollywood.
'I am younger than Janet but not as obviously youthful,' he asserts. 'However, I am not particularly set in my ways. The stuff I've done has always had a vaguely subversive flavour to it because that's what interests me . . . I am only content when I am skirting around trouble. I think I'm probably quite similar to Janet.'
Maybe. But with his highly personable manners (softly spoken and courteous); obvious intellectual gifts (a first in English from Balliol) and indifference to designer labels, Whiston's style is more suited to the common room than the bar at Groucho's.
But is he in touch with his audience? 'The one thing I share with them is impatience and restlessness with old forms of TV. I need to channel-hop. I cannot watch one programme all the way through. I tend to watch youth-targeted programmes - I watch The Big Breakfast, I watch Don't Forget Your Toothbrush. I also watch Fantasy Football. I watch a bit of soap and a bit of comedy. In that, I don't think I am any different from anybody between 16 and 24.
'The BBC has recognised that the youth audience is the most mercurial and the most demanding. They demand that things look fast and smart, but as soon as they sniff that things are over-styled they'll be off like a shot. It's finding the balance between something that seems anarchic but has actually got a lot of clever intent. There is no magic formula for getting this audience, but there is a one for getting it wrong - pretending you're hipper than you are.'