Yet another email arrived from Duncan Garner, TV3's political editor, and now grand inquisitor on that new, extremely important sounding show for political junkies: The Nation. He must be an extremely important chap about Wellington.

He must have gravitas. I was meeting him for lunch. The email posed an important question: I'd have him back to work by 2pm, sober enough to cover Parliament, wouldn't I?

Gravitas? He is only 36. This information took a bit of getting. I asked. He said: "How old do you think I am?" Why can't he just answer? I did ask that too, but I'll have to provide the answer: because he's a journalist who interviews politicians. So he not only likes to ask the questions, he's mastered the art of not answering questions from politicians.

If you want to make him roar, say: "You're becoming a politician."

He roared. "No, I'm not! I can't stand them." He had a supplementary thought. "Some of them are all right." He doesn't mind Annette King, Gerry Brownlee, Grant Robertson, John Key, Phil Goff. That's an interesting list. It's a list of politicians he's had a drink with.

I admire their stamina. They probably know better than to meet him for lunch. (Or to get into an email exchange with him: he is a relentless emailer.) If he'd had his way I'd be lying in a Wellington gutter while he, fresh as a rather large daisy, would no doubt be strutting about Parliament in one of his fancy suits, none the worse for wear.

He said: "Change your flight! I'll pay!" This was three hours later. I'd already told his boss, by text, not to expect him back, so I suppose I started it, but I wasn't going to let him finish me off. So I wobbled off to catch my flight and he carried on for a couple more.

I have no idea why he wanted to spend hours with me except that he is hugely convivial. And, because he regards almost everything, but particularly interviews, as combat, he did seem to enjoy me shouting at him. I don't generally shout at people in interviews; he drove me to it.

I hadn't meant to get stuck on the drink (not as a line of questioning, at least) but people do wonder about political journalists drinking with politicians.

He saw this as an attack: was I suggesting bias or mateyness? I'd asked whether he thought some people thought he was too matey with John Key. He could have just said: "I'm not", and it was a question about perception. But he said: "I don't think he'd describe me as a mate." He was being a politician again. "Ask the question again," he said, rather proving my point. This is where I shouted. "Now you're yelling at me. I feel like I'm in trouble with the teacher ..." He was not remotely contrite.

Some hours, possibly years, later we managed to concoct a reasonable response. I said I thought people thought political journalists know secrets about politicians that they didn't tell. "A politician goes to a whorehouse and I know about it and don't report it? I don't know that. I wish I knew more." He uses what he learns over a drink for "insight".

There is a story about him getting a ride in Michael Cullen's ministerial car, dropping Cullen off, then commandeering the car to ferry him and his mates around Wellington bars. He snorted and said, "let me tell you the truth". It was raining, he and his mates were waiting for a cab, Cullen said "jump in", they dropped him 500 metres down the road and were driven another 500 metres to a bar, they got out. "I mean, seriously, is that a scandal?"

Some people might think that he tells us too much. He is criticised for over-stepping the line between reportage and opinion. Is it okay to call an MP "smarty pants?" He put his very important, political-editor-with- gravitas face on: "What are you referring to?" To the time he'd called Steve Maharey "smarty pants". That was wrong. It was "smarmy pants", which he has "no problem with". Did he get ticked off? "To use a Helen Clark phrase, I can recall talking about it with him [his boss, Mark Jennings], but I can't recall the details."

Perhaps it was a case of one smarmy pants recognising another? Do you think he answered that?

I asked a bit about his private life and he grizzled a bit. He wasn't a public figure; he wasn't a policy maker and so on. He was with TV journalist Mihingarangi Forbes for 10 years and they have two daughters. He now lives with his partner of two years, who has two daughters from a previous relationship. I said I understood his private life was complicated and he said, huffily, that he didn't think it was in any way unusual. He told me later, after a bit of prodding, that he also has a child with another woman. He'd played up a bit. "Probably." I later got a text from his boss to ask whether I'd asked -how to rephrase this? - prurient questions. (Certainly not.) Another text from his boss: "He says you had a lot to drink?" (Not quite as much as I was urged to.)

I emailed to tell him off for tittle-tattling and he replied, the smug bugger: "All journos need copy."

So, I'll tell you what he had to drink: the best part of a bottle of wine and five beers, plus two more after I left. Northing would give me greater pleasure than to be able to tell you he was rolling, and indiscreet.

Alas, the only discernable effect was that his cheeks turned a fetching shade of pink (which exactly matched his shirt) and he swore more, but no great surprise there, now, is there? I said: Is your nickname really Drunken Garner? He said, "do you know what? It's not, actually." He says it's a hangover (the sort of joke he'd make) from his time at TVNZ in the mid-90s when he came in after a big night out to find someone, "who, actually, I'd had a few drinks with over the years" had written Drunken Garner on the news list. Funny, eh? "Hilarious." Later he did an impersonation of this Drunken Garner on the stairs, posturing, hilariously, with a bottle of wine.

Anyway, he says he's now grown up properly, and isn't going out drinking anywhere as much because his dad, his best friend, is terminally ill and that's put things like boozing, and work, into perspective. That is private but I mention it because he did: he talked for a long time about how much he loves and admires his father.

So he can be a sensitive sausage, in his blokey way. I asked if he was nervous about his The Nation debut. He said he was, for the first show, but: "That's only human, isn't it?" He used to take comments personally and would think, "do I have to change my approach?" but now he thinks, "if they like you, fine; if they hate you, f*** it."

He kept saying: "Am I f***ed?" This was nonsense. He'd sent an email suggesting we book the table under Mark Sainsbury's name, so as to get star treatment. More nonsense. He liked the idea that, of those of his colleagues I've interviewed he would be "the fall guy. [John] Campbell survived, [Mike] McRoberts survived, [Mark] Jennings survived. I'm the Taito Philip Field! Ha, ha! Do you know what I mean?"

It means he's so competitive that he'd even take being the least liked as a victory.

He is relentlessly competitive. He talks about going head-to-head with his great mate and competitor, Guyon Espiner, at TVNZ, like the sports journo he used to be: "We're here to knock each other out." I asked about a rumour that he and Espiner collude on story angles which earned me one of his eruptions: "Complete crap. It's bullshit. I've heard this rumour. It comes from print hacks." I said, "of course you gallery hacks are the elite, aren't you?" I might as well have taken him a gift basket containing live grenades and a card inviting him to: Lob at will. At any given opportunity - asking for "a slab of butter", not elitist; going to the bathroom or "in a non-elitist way: I'm going for a leak"; having his picture taken: "I get the elitist lighting" - he lobbed.

Interviewing him is like having a long session of rough play with a bull mastiff puppy, one that growls and wags its tail at the same time. Even when he's driving you mad you can't help but admire his enthusiasm. I've never seen anyone drink a beer with such gusto. He seems to stuff half the neck down his throat as he does it, which is extreme blokey, or thirsty, behaviour.

If you ever meet him, don't shake his hand. He has one of those bone-crushing handshakes designed to let you know how tough he is. Pretty tough, I'd say, with a thinnish skin (he denied this) which is not such an unusual combination. I may have, after the aforementioned "lot to drink" muttered something rude about his swaggering, macho, telly persona, because that is how he comes across, according to me. He was outraged at this, so it was worth doing. He does outrage magnificently: he shouts, he swears, he blusters away, and then, 30 seconds later, it's all over. This is fun to watch and it's what he does for a job, really: works up some outrage, real or otherwise, to sell his yarn.

I wanted to know how ambitious he is and the short answer (mine) is enormously.

His was: "I'm ambitious for New Zealand." He thought this a terrifically good answer and it was - although it would have been even better had I twigged that he was mimicking the PM. He did it again later and said, "see, I'm taking the piss out of him!" This was by way of a belated riposte to the "are you too matey with the PM?" question.

He says there's pretty much no difference between him on the telly and off, that what you see is what you get, and that's about right. He's in equal measures annoying and - this is the really thing about him -enormously enjoyable. But he's still a dirty rotten squealer.