Last battle for jaw-jutting, ass-kicking, inexhaustible Commander Ashdown

IT'S 10.15am in Smith Square, and Paddy Ashdown is giving Slobodan Milosevic a ferocious drubbing. "Last September I was in a village outside Pristina where people had been machine-gunned and their homes looted and burnt," he tells a camera, vehemently. "Two days later, when I saw President Milosevic, I told him he was responsible, and that unless he stopped it, he would be indictable. And that process must continue, no matter what happens in the peace agreement ..."

He talks and moves very fast, his emphases as precise as a nailgun, his tone suggesting only a madman or a crook could disagree with (or stop) him. Technically, Ashdown is not here to talk about Kosovo at all, but to support his Transport and Environment spokesman Matthew Taylor in launching a policy initiative. Together they unveil a new poster on a Toblerone- shaped hoarding: "You Can Wait All Day For Public Transport" it shouts to an audience of 12. Vote Liberal Democrat, it seems to promise, and the buses will run on time.

Paddy poses, thumbs aloft, with Taylor and Sarah Ludford, his international affairs spokesman in the House of Lords. But soon the great man is back at the cameras and fluffy sound-booms, to give the Serbian warlord another kicking: "Two weeks ago, I spoke to the War Crimes Tribunal about what I saw, and said I'd provide any evidence that would bring these people to justice. Only last September, I stood in a village outside Pristina ..."

This is Paddy Ashdown's last campaign. On 11 June, the day after the European elections, he will stand down as leader of the Liberal Democrat party after 11 years. It will be odd to think of the hapless Lib Dems without their slit-eyed, clench-jawed, Mandarin-speaking ex-commando boss. Something like gate fever has put an unusually martial spring in his step as he sets out across the metropolis with three Lib Dem candidates who are standing as London MEPs.

In the Jaguar Sovereign, as we purr towards Southwark, Ashdown removes his jacket for the first time that day. Jacket-removal is something of a fetish with him. It's as though he cannot stand the constraints of Civvy Street worsted. "You don't mind if I get on with some work?" he asks, and buries himself in his papers. The morning's correspondence is two inches thick, and full of that characterful handwriting which suggests a cry for psychiatric assistance. There's a lot of headed writing paper, from the Lords and the Commons, from Borough Councils and non-political organisations: The Oyster Fair people in Colchester want him to open the proceedings. The Gandhi Foundation humbly request a lecture...

So what was Milosevic like to meet? "He was very urbane, very charming, he spoke very good English and he lied through his teeth," said Ashdown. "He told me there was no ethnic cleansing going on. I gave him a bunch of wild cherries and said, `These are from the villagers. They wanted me to tell you they've had nothing to eat but these for 10 days since your soldiers visited them'."

We roll up to a Day Centre for the Elderly, off Southwark Bridge Road. The local MP, and the Lib Dems' Health spokesman Simon Hughes greets Paddy with, "Hi, boss" and they proceed to work the room like two professional Lotharios on a Club 80-130 holiday. "Where are the naughty girls?" says Ashdown rubbing his hands. You notice that he never, ever, sits on a chair. He perches on the radiator. He parks himself on the corner of a stool, as if about to spring into action. Two dozen old ladies sit at six tables, white-haired, crepe-skinned, as sweet and inoffensive as balls of wool. "Do you come here often?" he asks one of them. "Do you live by yourself? What do you do at weekends?" He leered at a crumbling platinum blonde in a shawl. "The chief reason you come here is the orgies, isn't it?" The ladies titter like clucky hens at this blue-shirted Chanticleer in their midst.

Paddy's pager goes off. Making use of whatever is available, like a good soldier, he plonks it on the table in front of a bewildered vieillard. "Do you know what this is?" he asks, guiding her hand onto the violently vibrating rectangle. She raises a face in which puzzlement wrestles with consternation. But he has moved on to discuss the over-80s 25p bonus ("It's an insult, isn't it?") with her neighbour.

Simon Hughes makes the speech, about the local Labour-run council's cuts in funding and the closure of elderly care establishments as the money is redirected into children's services. Hughes assures the assembled ladies of the LibDems' commitment to centres like this. Paddy looks on fondly, as if watching a favourite son.

We sweep on, to Guys' Hospital, to inspect the spanking new, if unfeasibly named, Guys, Kings and St Thomas School of Medicine and Dentistry. Though funded partly by private money, it's in a Lib Dem constituency (North Southwark and Bermondsey) and is being presented as a shining example of public/private sector collaboration. A large French engineer called Patrice with his arm in a sling greets Paddy with a Gallic shrug. We are quite a throng, wandering in our hard hats through corridors and empty laboratories. Ashdown's 24-year-old driver, Michael, a bright Oxford English graduate turned "Lib-Dem anorak", has become Keeper of the Leader's Jacket for the duration. Paddy bustles through classrooms and cloakrooms, asking obvious questions ("And this takes how many students? And can you use it for pharmacological classes too?"), never at a loss. He perches on a work surface, he leans forward with chin out, pugnaciously need-to-know. His shirt is always straining at the shoulders. And he isn't afraid to depart from the script and the flood of vapid, Is-that-so? responses expected of him. "In 10 years, when I'm no longer leader of the Lib Dems or anything else," he says with a faint sniff, "we'll be saying, What do we do with a lot of redundant school buildings?". The school principal, Sir Cyril Chantler, takes this on the chin.

Then, in the lecture theatre, with its seats raked like a cinema, Ashdown goes quite mad. Standing by the scaffolding, where two of Patrice's troupe are working at the ceiling, without warning he jumps up, swings round on a metal tube, spider-monkeys his way to the next level and with a final ally-oop, (and a "Comment ca va?" to the men above) hoists himself to the top. It's a startling display of pointless, look-at-me athletics. God knows how the workmen greeted the sight of the 58-year-old Liberal Democrat chief swarming like a pirate up the metal rigging, saluting them in cheery Franglais.

Before lunch Paddy checks out the Clinical Skills Centre. We encounter horribly lifelike prostheses: a plastic arm, leg, lump of skin, diseased organ or appendage of shame which can be worked on, injected, sliced or stitched as if they were human, but without all that blood. Ashdown is entranced. He bares his arm to show Dr Jane, the clinician, the scars where a Borneo wound was sewn up by "a ham-fisted Marine" who used soldier ants as rudimentary sutures. He looks through an auroscope into the ear of a female mannequin, as a plastic ruler depicting scenes of ear infection is pushed in her cranium: the photographers jostle for the perfect shot, Ashdown, former commando, appearing to dispatch a terrorist by stabbing her in the head with a toothbrush.

In the Jaguar, I asked about the future. Back to diplomacy? "The next thing I do with my life will be the last thing I do with my life," he said grandiloquently, "so I'm going to choose carefully. Yes, I'm interested in Kosovo, yes, I'm interested in writing, and in broadcasting and gardening. I've got a novel in my drawer I'd like to see if I could complete. Since I was elected I've kept diaries, though I kept them for my grandchildren rather than for publication. I'd like to play a part in the Euro-referendum when it comes up - any part I can play in ensuring we build the kind of Europe we need to build."

Then we were back in Rhetoric Alley once again, but it was ceasing to matter. Paddy was sweeping off to tackle more squadrons of fluffy-haired old ladies, to look concerned with councillors, congratulate kitchen staff and meet his public. He was becoming, in a sense, beyond politics, the old soldier leaving the battlefield, like the lonesome warrior on the poster of Saving Private Ryan, only walking away from the camera.

The last photo-op of the day is on a barge from Islington to Holloway on the Regent Canal. Photographers and Newsnight journalists swarm. Paddy poses in gubernatorial splendour, hand on the narrowboat's tiller, eyes narrowed, surveying the horizon. An unexpected urrent comes from the left, with neat symbolism, and rocks the boat.

And then, a hugely fat half-naked man on the towpath lurches towards the barge saying, "I know you. It's Mr... Mr...".

But Mr Ashdown has no wish to secure his vote and goes below. The man, clearly the worse for a lunchtime shandy, keeps on coming. Unable to stop, he lurches into the canal with a 25-stone splash, and disappears. In the ensuing panic, two Lib Dem councillors grab his hands and clamp them to the shore. He can't drown now, but is too pissed and blubbery to be pulled out. Then Ashdown appears (possibly alerted by his press officer, possibly on his own initiative) and grabs the stricken merman. The TV cameras whirr. Ashdown's Special Boat Service training returns. "Sailor's grip, old boy," he says, enveloping the man's paw in what looks suspiciously like an International Peace Handshake. With four others, he manoeuvres the leviathan onto the bank. "All I wanted," he groans, "was Paddy's autograph."

All this action - all this climbing, flirting, life-saving, attitude- striking, jaw-jutting, ass-kicking and jacket-removing ... Ashdown is as exhausting as a three-year-old boy. As the Jaguar sweeps into the Commons, the mood is buoyant. "In theory you've only got eight days more in this parking space," says a press officer. "We must work out what to call you in future," says another. "I'm definitely not ready for Elder Statesman," says Ashdown firmly, "nor Eminence Grise". "Party Luminary?" suggests the driver. "Fading Luminary," says Ashdown. "How about Elder Fading Luminary?" says the press guy.

They're still at it as we part. Good luck, Paddy, I say. He doesn't stop. The rest of his life is waiting, tapping its foot impatiently.