"One shouldn’t kid oneself. Being dull is not really forgivable," Ian Hislop murmurs, slightly sternly. His office in the Private Eye building is strewn with back issues, newspapers, pictorial jokes about Fox News, a piano and, one imagines, an unspeakable volume of unsorted legal papers that have made his life and career anything but dull. The building itself is shabby, run-down and oddly quaint, an appropriate setting for the production of Britain’s leading satirical publication – a magazine that has become an institution in its own right, reluctantly adored even by the hacks, politicians and actual institutions that it scorns.

Despite his busy schedule, Hislop is relaxed and affable – perhaps because it’s Tuesday. "Private Eye is fortnightly", he tells us, "which is just the most fabulous setup. Originally set up that way by people in the 60s because they were very lazy, whereas for us it works that we get to do other things. Nearly everyone here does something else as well, because I don’t pay them enough. The week accelerates from about Tuesday, and gets worse and worse until Monday, when we go to press. That’s a very hectic day. That’s a day when many of us behave a bit like Gordon Brown."

Whilst studying English at Oxford, which he professes to have loved, Hislop began a stint as a student journalist. "I interviewed Richard Ingrams, who was Editor of PE then. My mother then saw an interview with Ingrams in which he said he was looking for new blood. So I wrote to him and said, ‘I’m here and it’s high time you employed me.’ He said ‘Why don’t you send me something?’ so I started sending him jokes. That’s how I got my foot in the door and sort of… hung around."

With his natural humour and prolific writing Hislop flourished at the early Eye, although it was partly down to his friendship with comedian and owner Peter Cook that he became editor. "A lot of people thought I shouldn’t take the job. A lot of people who thought it should be theirs. Lots of 40-year-old men were very unhappy. And they tried to stop it by taking Peter Cook out to lunch. They made the classic mistake with Peter, who liked lunch, but not food. They all had a huge amount to drink, especially Peter. He came back to the office, completely forgot what they’d told him, shook my hand and said, ‘Welcome aboard!’ So the coup petered out. And then I sacked them."

Hislop has been at the helm for over two decades now, but he prides himself on simple victories. "My greatest achievement is that it’s still going. Just surviving in the print media I think is pretty good." Despite the woes of Fleet Street, Private Eye’s sales figures have gone from strength to strength in recent years, with the latest statistics suggesting it’s more widely read than The Economist (although less than Freemasonry Today), perhaps due to its humour in otherwise bleak times and determination to confront head-on the forces that can and do restrict other papers. "The best thing about the Eye is that it’s a club. You can read it and say, ‘I’m not entirely impotent because my local councillor has done this’ and write in. We will read it, and get someone to put the boot in if necessary. For readers that’s very empowering." He’s enthusiastic about the Eye’s influence too, although not unrealistically so. "Sometimes I think, what’s the point? Other times we can sometimes crystallise the debate, kick it forwards – and we can certainly break stories that nobody else wants to run." Good journalism or good business? We ask how many times he’s been hauled into court. "Oh, I don’t know… 40? 50? I’m not averse to legal action, I’d be mad if I was. Most sued man in Britain? I don’t know anymore, because the libel’s slightly tailed off and privacy’s taken over." He is unsurprisingly derisive about the UK libel laws. "Libel becomes stupid when you’re stifling scientific debate, free debate and general public interest, just because a few libel lawyers have become very specialist in persuading judges to close things down."

And what about privacy? "What the public is interested in isn’t necessarily the same as the public interest, and I totally accept that. What I’m for is a defence that says: this is information that should be presented to the wider public because it affects the way they carry out their public life. What’s the top case in privacy? Oh God, it’s Max Mosley being spanked. It’s hard to present a serious face about the evils of a privacy injunction when you’re talking about a man dressing up in a German uniform and having his arse paddled."

In the face of exorbitantly expensive libel cases, one wonders what could possibly motivate him. Righteous anger? Social justice? "Deep psychological problems, probably. I really don’t like being told what I can and can’t print, that’s partly why I hate the privacy thing so much. Getting a note from a lawyer telling me that a story’s not for public consumption makes me think that it should be, almost by default."

We discuss the coming election, and whilst he’s tight-lipped as to how he’s voting, he’s adamant that he will. "I do think it’s everybody’s duty to vote. I get very pompous and shirty about this. Someone said it’s as important to vote as it is to laugh at your politicians, and I do try to get the mix right. I try to vote for the party that I think is least worst." His criticism of Labour is surprisingly measured, however. "They were just a bit timid. There was none of that boldness, that bonkers energy. They’ll look back and think, ‘Well, we got in, but what did we do with it?’" Is this kind of impotence the cause of Obama’s midterm poll wobbles? "Yes, but he wasn’t helped there by massive over-expectation. Yes, everyone sang when Blair got in, but they didn’t think he was the Messiah. In America there’s this zigzag of emotion that the public seems to be able to go through, from ‘He’s more or less god’ to ‘He’s this faggy liberal Commie who’s trying to destroy the United States’".

Asked whether he thought News Corp was a threat to British well-being, he replied, "Yes, they always have been. That’s a fairly simple answer. If I defend the BBC, people say it’s cause you work for them, but I’ve always defended them and I believe in public service broadcasting, whatever its faults. A version of Fox News in Britain is deeply…" he tails off. Would the Brits consume it, were it offered? "I have an awful feeling they might. I’m sorry, I don’t think that badly… It’s not that The Times or Sky News never do anything good. It’s the ambition, and the desire to murder everything else. I like Sky Plus. It doesn’t mean I think right-wing lunatics should be allowed to tell lies, live on air, and then pretend it’s balance."

His distaste for American media is tempered by a seeming affection for our own. "Britain’s broadcasting is not hugely logical but it has worked hugely well. A lot of things that you think are part of the BBC aren’t. They’re just part of a culture of quite good broadcasting. It’s always been dysfunctional, but that’s true of a lot of things that aren’t planned. That’s Britain for you, isn’t it?"