Hugh Orde, the Northern Ireland police chief denounced for advocating talks with terrorists, is not backing down. Could he soon be running the Met?

On the table in Sir Hugh Orde's office at the Belfast headquarters of the Police Service of Northern Ireland (PSNI) is a copy of Douglas Hurd's biog raphy of Sir Robert Peel. Could there be a more apposite book than one about the man who gave us the word "bobby" and whose time in the 19th century as chief secretary of Ireland still arouses strong emotions there?

Orde is being talked up as a potential successor to the embattled Metropolitan police commissioner, Sir Ian Blair, just as his own PSNI officers are being targeted by dissident Republican paramilitaries in what is seen as the greatest security threat there in a decade.

"What you see here at the moment is the communities moving forward and that is unstoppable ... We know [paramilitaries] are still trying to recruit; some of those we are arresting are young people who would have no notion of what it was like in the troubles - the 'glorious days of revolution' that never existed stuff - and people who are pretty unbalanced and dysfunctional. But they are dangerous ... we know they are determined to attack and kill police and we have been lucky, frankly."

Famously a long-distance runner - "I am getting slower and slower" - and a fan of Bruce Springsteen and Leonard Cohen, Orde, who turns 50 on August 27, holds one of the most senior positions in the police and may be on the brink of the top job. Originally from Haslemere in Surrey, he wanted to be a farmer but joined the Met instead in 1977. This was a time when a "Life on Mars" police culture still thrived. He can recall being a young cop at Rochester Row station, where the sergeant would leave a police helmet on the front desk and hide if a member of the public came in, turn the lights on and off and intone, Dalek-like: "This is an automatic police station, state your business."

Orde shakes his head at the memory, saying: "Some poor victim would have a conversation with a police helmet."

Orde went to Northern Ireland as part of the Stevens inquiry into the links between the security services and Loyalist paramilitaries. Was he surprised at the level of collusion? "Collusion, the C-word. First, we have to be clear there was, without doubt, collusion, in some cases between security services and the paramilitaries ... Was it endemic? No, it was not. Was it institutionalised? No, it was not. That doesn't mean it didn't happen."

That Chris Patten, chairman of the independent commission on policing for Northern Ireland from 1998-99, allowed people to "leave with dignity, at huge cost to my organisation in terms of experience, was critical", Orde says, referring to 3,360 officers who have since left under the Patten plan, partly as a result of the decision to cut police numbers. "It did give people an opportunity to move away, if they didn't want to be part of a new world."

His answer may be an indication of the tightrope he still has to walks since becoming chief constable of the PSNI in 2002 - even in the "new world". While Orde has to acknowledge what happened in the past, he needs to do so without, as he sees it, alienating the people whose support he needs in the new, post-RUC police service. "Generally speaking, in Britain, senior leaders of the police service are pretty anonymous," says Orde. "Here, it is totally different and I misjudged that badly ... everything the police did was interpreted in a political way and in directly opposing ways by different sides."

He also found his job has taken him to the US. "The obsession with Northern Ireland - and particularly policing - on the east coast of America was something we identified very quickly as needing to be dealt with. Was that police business? I would argue that it was. The work we did in the States for the last six years has been unravelling 35 years of a very one-dimensional interpretation of policing, the Republican agenda, and turning that into an accurate description of what policing actually was."

He has spoken to Hillary Clinton as well as George Bush, who he visits "once a year to tell him about policing and that it's working. It's not the content of the conversation that's important but that the conversation that takes place."

But whoever takes over from Blair will have a different terrorist threat to worry about and Orde defends what he said to the Guardian this year, that one day we may need to talk to al-Qaida.

"I got flak last week for speaking to the representatives of [loyalist paramilitaries] the UDA," he says, before asking whether I had read what was said about him by Lord Maginnis - the former Ulster Unionist party's security spokesman described Orde's actions as "unbridled arrogance and patently idiotic". "Wow, he hates me with a vengeance. I have a very basic benchmark: I will talk to anyone who wants to make a contribution to policing," he says, adding that he initially faced criticisms for talking to leading Republicans. "I fully understood that it would be deeply offensive at the time to talk to some of the people I spoke to but it was the right thing to do because it moved the world on."

Orde warms to his theme, explaining that had the Edward Heath government's clandestine talks with the IRA been made public the outrage would have been enormous.

"When I first met them, I put an email out saying, 'Here's what I'm doing and here's why I'm doing it.' Most cops with a lot of service said: 'Good luck; if this means my kids don't have to go through what I went through, I'm all for it'."

Gesturing at the crowded bookcases, Orde says he has "learned more from eating fish and chips" with David Ervine, the late former leader of the Progressive Unionist party and a one-time paramilitary, about "working-class loyalism" than reading any of those books. At some stage, there will come a point when speaking to the unspeakable will happen and the role of the police is to create the conditions where people realise this [terrorism] ain't going to work."

What he was also trying to suggest earlier this year, he says, was a way of diverting would-be terrorists. "The point was - an awful lot of people who are so-called al-Qaida are actually radicalised, young, disenfranchised British. The more you can get into those communities and build confidence in them, the more chances you have of making them see the crazy way they're going."

Orde supported extending the detention without charge for terror suspects to 28 days. But he says the argument over whether the time limit is seven or 28 or 42 or 90 is "completely sterile".

"What we must have is a system in place pre-event because all the lessons from knee-jerk legislation, from the dangerous dogs act onwards, is that you get something unworkable, chaotic and probably more Draconian.

"My fear is that, in the absence of proper legislation ... the temptation will be to charge people early, to take risks and it will fall apart 10, 20 years down the line."

The decision to extend the detention time of a terror suspect should be left to a senior judge, he says, rather than to an arbitrary time limit, as "if that means, on day 28 and one second, someone who I suspect deeply of a huge outrage, that I cannot charge them with, will walk out the door, society will have to judge government on that, not me."

It was in the wake of the July 2005 London bombings that Jean Charles de Menezes was shot, and next month's inquest may yet force Blair out of the job he has refused to relinquish. Does Orde sympathise with the Met commissioner?

"My basic point has always been if you can't take the heat don't apply for the job, but these are hugely challenging events, which is where leadership is always tested ... If you take a senior position, expect to be under the spotlight. That's the world we live in."

Last year it emerged that Orde, who was married at the time, and a then undercover officer, Denise Weston, had had a child. They are now officially a couple, but the relationship attracted hostile comment in the press.

"It was tiresome and hurtful at the time but I have no difficulty with a journalist making observations about my personal life, provided they're accurate," he says. More damagingly, he was accused in the press of taking a family member on a paid-for trip abroad. He is now suing for libel and is confident of success.

"When someone says something that goes to the heart of my integrity around money, which is a downright lie, I think you have no option [but to sue], when they refuse to retract it. But you've got to live with what people write."

So, what about that job at the Met? "Help, Liz!" he calls out to his press officer before saying he has agreed to stay at the PSNI until 2010: "It is a great privilege to run this organisation and I have no plans at all to move at the moment. But one day?"