Two Fleet Street legends combine with the relaunch of Punch. Photograph s by Roderick Field
"It's a ghastly thing, humour," said the editor of Punch, gazing with mock sorrow into his tomato and basil soup. "Muggeridge once said that English is the only language in which the term 'trying to be funny' is a dire and terrible insult. I've been thinking of having a cartoon in the first issue, showing Richard Ingrams and Ian Hislop and Angus Deayton facing a firing squad, with blindfolds and last cigarettes, and the head of the firing squad is explaining to a reporter and saying, "Trying to be funny, I believe, sir."

He laughs delightedly, as he does so often during lunches, dinners, boardroom meetings, editorial conferences, old-crony reunions, hack swarms at El Vino, marriages, funerals. Peter McKay is an Olympic-standard laugher, a chronic gigglepuss. He could be relied on to laugh during an exorcism. So many things about the modern world amuse him or appall him, he seems to spend half his life in helpless and snorting derision. This may be sufficient reason why, when Mohamed Al-Fayed decided to resurrect Britain's best-known, if hopelessly outmoded, humour magazine, four years after it was declared dead, he sent for the man Fleet Street used to call "McHackey".

The new-look Punch comes out on 6 September, re-designed and repositioned in the glossy-journal market. From its glamorous new premises in Knightsbridge, its 20-strong staff will aim for an ambitiously large (the first print run is 400,000) and reasonably well-off (pounds 1.80 a throw) readership. But who will they be? "Oh, every intelligent person from 25 to 45," says McKay with breezy confidence, "although the age range goes well beyond that." But he confesses that he couldn't remember ever buying a copy in its glory days.

Given that Punch has, in its 155-year history, taken in stout-party Victorian pratfalls, Muggeridgean satire, political lampoons, Coren literary parodies, and frantic undergraduate frolics under its last editor, David Thomas, what style of humour is he keen on? "We want to get away from the idea of a 'funny magazine'," he says. "I want humour to come out of proper articles. I'm sure you, like me, yelp with laughter at things in the daily papers which are straight articles, not written to be funny. All you can do is produce a magazine which amuses and informs and entertains, and hope that by doing so you'll come up with staggeringly funny pieces." He has signed up some fancy contributors - book reviews from Edward Said and Julie Burchill, Alexander Cockburn on America, Hugh McIlvanney on sport, a column by Alexander Chancellor, a regular slot by the magazine's literary editor and famed odalisque Lucretia Stewart ("She's going to write a column, called 'The Ancient Secrets of the Human Heart', which will, I hope, be pure unadulterated filth") - not all of whom are renowned for their uproarious wit and power to convulse a snug.

Would there be anything for stand-up-comedy fans? "Och, I don't want alternative humour," says McKay, in his sweet, old-fashioned way. Now 54, he has looked the same for 20 years: broad pudgy face, the approximate size and shape of a 1950s Rediffusion television set, merry blue eyes sometimes lost in crow's feet of amusement, and that curious hairstyle that starts way back on his scalp, a la the man in Eraserhead, and curls up into dark, oily tendrils. It's the work of a Mr Webb, apparently, from Deddington in Oxfordshire, and costs the parodically thrify Scot five quid a session.

What made a good editor? "Muggeridge was capable of being funny himself, but like a lot of brilliant writers, he wasn't good at organising other writers. What he was good at was attracting a good gang, because people liked him. Bill Davis wasn't particularly funny, but he was a good manager and enthuser. He'd say, Look, the sun's shining, it's holiday time, let's be funny about holidays - and he managed to persuade a lot of British people that that's what humour is about."

He is modest about his entitlement for the job of Fun Commissar. "I don't know if I have any credentials at all. I wrote a few things for Punch years ago, but I've never written a 'humorous' column. In fact, Miles Kington wrote somewhere that I'd never written a funny line in my life. I was rather hurt. But I think I was hired because I'm a newspaper person and they wanted to make it more news-reactive."

He is, indeed, a newspaper person, the way Sir Terence Conran is a menu person. McKay is the hack's hack. Most journalists over 35 have "McKay stories" to tell. His foreign jaunts, expenses claims, practical jokes, gossip techniques, rows, vendettas and rumoured affairs have been handed down, man to boy, through generations of editors and correspondents. My favourite is the story of Norman, the Daily Express sub-editor responsible for laying out McKay's "William Hickey" page, a gambling enthusiast who used to desert his post every day, dangerously near the deadline, and nip round the corner to punt on the 3.30 at Kempton Park. One day, to teach him a lesson, McKay got the page designed early and in secret. When the hapless Norman returned from the bookie's, he found himself locked out of the office. Through the glass panel, he could see McKay and his staff drinking champagne with apparently suicidal disregard as the layout deadline came and went. He pleaded. He sobbed. Finally, he demanded: "Why are you doing this to me, Peter?" "Because you're Jewish, Norman," snarled McKay with massive irrelevance.

At the Evening Standard, where he and I worked together in the last years of Fleet Street, one learned to dread the McKay wind-up routine. On my second day at the paper, I was standing apprehensively outside the editor's office when McKay glided up behind me. "You luke pensive, Mr Walsh," he cooed, Iago-like, in my ear. "And you have much to luke pensive about..." His influence was extraordinary. For a period, nobody ever picked up a restaurant bill without, McKay-like, going "Whaat?" at its extravagance. He popularised the concept of the Shop-Your-Granny hour, when a thin Diary was about to go to Press.

As readers of his Evening Standard column will know, his childhood was a Tom Sawyer idyll of small-town decency among the "fisher-folk" in the frozen tundra of the Scottish Highlands. McKay never knew his father ("He disappeared in the war") and was brought up in the village of Portgordon by his mother and a spinster aunt. He writes about growing up in the Fifties with a rapt particularity that goes well beyond nostalgia. He walked into a job on the Scottish Daily Express after writing to the paper in support of American nuclear bases on the Clyde.

Stories of watery tragedy were commonplace beside the Moray Firth - the words "Women wept by the harbour wall" introduced so many stories they became a cliche - but one led to McKay's finest hour. "We went to look at a ship that had been missing for three weeks. It had been written off as lost at sea - we'd published pictures of these supposedly dead souls - and one day it just sailed into Aberdeen harbour with its masts down. It had been caught in a storm and taken shelter in a Norwegian fjord, not knowing about the hue and cry - a fantastic story. But the other papers were there already, interviewing the crew and taking pictures. Then my photographer said: 'Wait around afterwards, I've got an idea.' And when the other journalists had gone, we drove to the ship and said to the skipper, 'Can you just take the boat out and come in again?' We offered him pounds 20 and he agreed. We photographed it from the fish market as it steamed in between the piers. Next day, we had the whole front page, with the photograph headlined 'GHOST SHIP SAILS IN'. We scooped the pool."

The family of an early girlfriend, Mabel Pirie, were members of a religious sect called the Exclusive Brethren, run by "a mad American evangelist". When McKay discovered the sect's alarming rulebook, he knew he had a scoop. And since the local paper wouldn't touch the story, he contacted the Daily Express in London who jumped at it. McKay was summoned to the metropolis by John Junor, the growly editor of the Sunday equivalent, and his Fleet Street career began in a blaze of glory at only 21.

Junor - the pooh-poohing, I-think-we-should-be-told sage of Auchtermuchty, became his mentor and remains a close friend. "He's got a marvellous nose for what his readers really talk about. And he's very funny, sometimes unconsciously. When he gets into one of his ranting rages, I just burst out laughing." What had Junor taught him? "He taught me that everything has to be new - that if a story's appeared anywhere, even in a local paper, it couldn't appear in the Express. And you couldn't run a gossip story unless you spoke to the people concerned, even if they flatly denied it."

McKay's education into the art of the possible continued elsewhere: "There was a bad road crash near Staines, lots of casualties, and I roared off with a photographer to report on it. Before we left London, he said, 'Just got to pop in here', and parked outside a toy shop. Then he came out with two teddy bears. 'Look', he said, 'do you want to have pictures of just bits of tin all over the road?' He was taking the bears along to toss into the wreckage."

It was gossip, however, that proved to be McKay's metier, on the Sunday Express's "Town Talk" and the Daily Express's Hickey page. From the earlier period dates the occasion when his assistant, the future MP Lady Olga Maitland, was attempting to interview Aristotle Onassis, the Greek shipping magnate, on the telephone. McKay silently pushed a note across, suggesting she confront him about his damaging feud with a Mr Epiglottis. "One last thing," cooed Lady Olga. "Have you patched up your feud with..." The effect, as McKay tells it, was electrifying. "Whad you talk about?" demanded Onassis. "Is crap, is never happen. Epi-whatty? I never fucking 'eard of 'im. What are you, the fuckin' police? You ask me about people I never fucking 'eard of?"

His happiest times were spent on Private Eye, where he wrote the Grovel column with Nigel Dempster. Though he and the magazine later fell out after McKay's history of the Eye was published ("He said that I'd accused his father of having a homosexual affair with Jean Cocteau"), and despite its hilarious "Peter McLie" parody of his faux-naif style, he remains a fan of Richard Ingrams: "The only man I've ever sat at a desk with, crying with laughter". After years of rows and patchings-up, it's the old Grovel style he's most anxious to replicate at the front of the new Punch.

All this laughter - does it ever subside when his cronies are out of earshot, and does McKay the sentimental Tory throwback reveal a nasty streak? It's possible - McKay admits there's nobody he wouldn't stitch up if occasion demanded - but there isn't a hypothesis that survives meeting him for five minutes. Put it this way: I have never met a human being who enjoys himself as much as Peter McKay. Puffing a pounds 13.95 cigar in Harvey Nichols's restaurant, describing the still-unravish'd bride that is his new magazine, he is a soul in bliss. And when his legion of critics gets medieval on his ass, come 6 September, the experience will just throw up yet more funny stories for his repertoire. So life is OK? "On the whole," he says, "it's better than waking up next to a dead policeman." And the endlessly amused Mr McKay shakes with delight