John Walsh meets... Sue MacGregor, woman of Today

The serene voice of Radio 4 confesses how she longs to be wanton. Photograph by Louis Lazo

I suppose if you have to be dragged from your slumbers at 7 o'clock on a Tuesday morning to hear that the leader of the free world has just pressed a button and sent 27 cruise missiles on their uncompromising trajectory into the backyard of the world's most unstable dictator - if you must have this news dinging in your ear at such an ungodly hour, better that it should be brought to you by Sue MacGregor than anyone else. No one can make bad news sound more bearable, cabinet ministers sound more shifty, Middle East peace talks sound more intelligible or pretentious academics sound more hollow than the chatelaine of Radio Four's flagship news programme, Today. Even the brisk weather forecast sounds more plausible when delivered in her calm and reassuring voice, that zephyr upon the waves of current affairs.

"I know, I know," she says sadly. "I know I'm called 'Nanny to the nation' and so forth - but none of my friends would recognise me in that description. It must be the tone of voice. People say it's so sensible. But I long to be un-sensible. I long to be wanton..."

Interesting word, "wanton". Its primary meaning is "playful", as in sportive, gambolling and capricious; but it also carries connotations (especially when applied to a woman) of "licentious, unchaste and lewd". Naturally, Ms MacGregor means it in its politer sense, but there's undeniably something rather sexy about her hold on the nation's collective male consciousness. To the average slumbering lout, her tough-but-playful on-air fencing bouts with politicians get translated, through some hormonal encoding mechanism of the middle ear, into the essence of post-feminist heroism. It is no surprise to hear that her postbag routinely features letters from "weirdos who send me cards saying I've been sending them messages through the airwaves, and marking proposed meeting places on a map".

What messages did they think she'd been sending? "I've no idea. But there's another man, a much cruder person, who sends me unspeakable - I mean really unspeakable - things through the post." Ms MacGregor looks frankly aghast. Gingerly, one asks: What sort of things? Unspeakably organic things?

"Yes... Yes."

Unspeakable things of the kind you might buy in Boots the chemists?

She shudders. "A mixture of the two." (Yeesh.) "But the police are on to him now."

Most of Ms MacGregor's listeners have a more warm and respectful attitude towards her; unfortunately they're not the ones who write to her. "People tend to write to complain, don't they?" she says without rancour, "rather than to say, 'Hello, you're doing a reasonable job.'" She gets taken to task by pedants over the oddest details. "People tell me I say 'the Reverent' instead of 'the Reverend'. They write and say, 'There is a difference, you know - look it up in a dictionary'. I always write back saying, 'I think you must have misheard.'" She laughs at how trivial listeners can be, but a moment later is still trying out this linguistic crux on her tongue. "The Reverend John Smith. The ReverenJohnSmith. You see? If you say it fast, the 'D' gets buried."

Such devotion to the broadcaster's art. But then Sue MacGregor is a devoted woman - loyal and true to the BBC, to Today, to the listeners and to a career that has, to a large degree, taken over her life. Immaculately polite and charming, she shies away from intrusive enquiries about her private life, and objects to the tabloids' occasional portrayal of her as the childless spinster of the airwaves, a bride of the Corporation. "I've been in love perhaps four times," she says, "And the last time wasn't that long ago. I'm reasonably single these days, though I wouldn't say I lead an entirely monastic life." Nonetheless, it's hard to imagine her ever being wholeheartedly (or wantonly) off-duty. Her conversation is studded with warm references to her employer and co-workers. Our interview, conducted in the fronded colonial bar of the Arts Club in London's West End, is the prelude to a lunch with two colleagues from The Heritage Quiz, which she chairs for Radio 4. Although this is one of her days off, she is discussing the next series. What else, I wondered, did she do on a non-Today day?

"It usually starts with waking up at 3.30am and thinking, 'Oh wonderful' - wasn't there a French king who had his slaves wake him up early, just so he'd know he had another two hours to sleep? Then waking properly at 7am, and religiously listening to my colleagues sailing superbly though the next two hours. Then I often go to my health club, where I try to tone the odd flabby muscle."

She lunches at the club or, "if somebody else is good enough to entertain me", at the Ivy. If it's with "a pal" or with "chums" (she is keen on Angela Brazil formulations), they may go to Limonia, a Greek taverna in Primrose Hill, or a Golders Green establishment called Laurent, "run by a Sicilian Tunisian who makes the best couscous north of North Africa".

She turns down most offers for voice-over work but will chair the odd business conference, as a kind of freelance Voice of Reason. She sits on a Foreign Office-inspired committee for sending American postgraduates to non-Oxbridge universities, and on another that seeks to establish the key ethical issues in modern medicine. And her day necessarily closes down early, with an early night before the pre-dawn summons to Today.

Has she given up going to dinner parties? "I have tried going and leaving early. Kind hosts always say, 'You can leave after the main course' - but we all know that in London that's about half-past 10. I can do drinks and very early supper round the kitchen table, but, faute de mieux, lunch has become more important than dinner."

I know journalists who have recurring sweat-drenched nightmares that they've somehow turned up on Today and, in the midst of the programme's rapid-fire agenda, find themselves having to interrogate a brace of Druze militia on a crackling line to Beirut, or interview a sneering Treasury economist about interest rates. Death by firing squad seems preferable to having the gaps in your learning revealed on the air. Did it bother her?

"It's fatal to admit to having gaps. But there are various things that save you. One is that if it's a story that's just broken - like all the present stuff about the Turks and the Kurds and the KP Peanuts... " [she allows herself a fifth-form giggle] "no one expects you to be an expert. And BBC correspondents are all past masters at that great question, 'Can you just remind us how all this came about?' But you've also got the back- up team, who are usually good enough to thrust a relevant cutting or wire story in front of you, just as the editor of Walid Jumblatt's newspaper is coming on the line. And, of course, there's a great deal of semaphoring - I wave my hands around like a cross between a Christmas tree and an old railway signal."

Sue MacGregor moved to the Today hotseat in 1987 from presenting Radio Four's Woman's Hour. Since 1984 she had managed to do both programmes on Mondays and Fridays, an experience she describes as "a challenge - my biological clock didn't know what it was doing". She considers the Freudian slip: "...Biorhythmical clock". At the time of the move, she was considered super-competent but perhaps excessively nice, a kind of benign headmistress.

Since then, the MacGregor style has modulated into a tougher proposition, with a faintly ghoulish streak. Private Eye lampoons her as "Sue MacGhastly", because of her fancied obsession with grisly details in crashed-airline stories. And a gradually-evolved sense of "cheek" lay behind a splendid row in April this year when the Conservative chairman Brian Mawhinney blew up at her during a live interview.

It was just before the May council elections, and MacGregor, reminding Mawhinney that in 1990 the Tories had "got rid of the poll tax and got rid of Mrs Thatcher", wondered if something equally dramatic was on the cards. Mawhinney exploded. "What you have just suggested to me in front of the nation is that we should dump the prime minister," he shouted. "That is a ludicrous and indefensible question!".

"When someone's in the studio with you," MacGregor recalls, "you can ask quite cheeky questions with a smile and they won't take offence. But he was down the line at the Westminster studio." She smiles fondly, as though recalling an elderly relative. "He was absolutely furious, I suppose, understandably. He went on about 'disgraceful, smeary-type questions'. I love that word 'smeary'." The listeners took her side. Faxes came chattering in, bearing the legend "Keep sticking it to them, Sue", and similar voice-of-the-terrace observations.

Although born in Oxford, she was brought up in Cape Town. Her father, a doctor, still lives there and she nominates her Club Class flights to the Republic as her only personal indulgence, apart from frozen Mars Bars. Arriving in London in 1960, she became a lowly secretary at the Beeb's Light Programme and was given a one-month contract for In Town Tonight. Soon after she was picked to be a reporter on The World at One with William Hardcastle, Jonathan Dimbleby, Margaret Howard, Roger Cook and a shoal of other nascent legends. Perhaps surprisingly, she is rather severe on both her early self and the Corporation's less-than-rigorous ethos. "When I joined the BBC, it was more like joining the Civil Service - you went straight in from university and retired at 60 or 65. There were an awful lot of long lunch hours and drinking at the George pub - and a marvellous club called the Marie Lloyd, where the drama people went - and sometimes not coming back at all in the afternoon. Even I used to indulge in this practice, at the age of 25, before they invented the PM programme." These days, she says, "you're only as good as your last programme. You're kept on your toes. More and more people are on short contracts. Everybody, no matter how long they've been here, worries that their face won't fit any more. And," she surprisingly concludes, "I don't think that's entirely a bad thing."

From the Hardcastle show she moved to Woman's Hour, which she ran with conspicuous success for 15 years. I reminded her of an electrifying exchange with Winnie Mandela in 1986, in the course of which Sue MacGregor ticked off the ANC's star performer and told her that her condoning of "necklacing" - death by petrol-saturated rubber tyre placed around an "informer's" neck and set alight - was a shameful and morally obtuse position. "I remember how her eyes went quite mad. There was a real flash. The mask dropped. But Winnie is two people - one is an enormously brave, charming, beautiful and delightful person, the other is Winnie Off the Rails. And they both came out in that interview."

She still misses the Woman's Hour audience, with whom she had an intense rapport ("All right," she would say to the fastidious old guard after a dodgy item on, say, transsexuality or flatulence, "you can take that disapproving look off your faces now") and worries about the Today-listening multitude: "You know there'll be people out there who are 100 times more informed about a subject than you are and are waiting to trip you up. I'm much more conscious of trying to get it right."

Why has she never done television? "Oh, if I were 23, with spiky green hair, I'd be more acceptable." But wouldn't she like to be the Barbara Walters of BBC1?" She all but clapped her hands. "I'd love to be, but nobody's ever asked me." Whom would she most like to interview? Boris Yeltsin? Fidel Castro? She shook her head. "Hillary Clinton. I met her once, at that famous breakfast at the American embassy. We were all longing to talk to her but she had to go through this rigmarole of pretending to be interested in us. So frustrating. But she's an enormously intelligent and interesting and important woman, and she'd be top of my list." The divine Ms MacGregor swept off to lunch, trailing blue chiffon. I trust that when the interview comes off, the BBC will bung me a small consultancy fee.