MARTIN McGuinness's mother was worried about him. It was 1972 and she had found an IRA beret and belt in his bedroom. He'd just given up his job and the newspapers were describing him as the officer commanding the Derry Brigade.

"His father is a welder, his brothers are at the bricklaying and carpentry but what will become of Martin?" she fretted. Next week, Martin will be installed as deputy first minister of Northern Ireland and Peggy will be there to watch.

"She's a hale and hearty 83. With the help of God, she'll be at Stormont on 8 May, " says McGuinness.

What's likely to be on his mother's mind as he makes his pledge of office? "Did Martin get his breakfast?" quips a Sinn Fein aide.

Parliament Buildings, Stormont, is buzzing as the big day approaches. Our Lady of Mercy and Hunterhouse school groups, Italian visitors, even rugby teams, tour its marbled splendour. Officials frantically try to work out how they'll fit everybody in on Tuesday week.

Senator Edward Kennedy, ex-senator George Mitchell, White House representatives and a host of former British secretaries of state . . . to name but a few . . . all want to be there to witness what many thought impossible: the DUP and Sinn Fein forming a government.

McGuinness and Ian Paisley are probably the oddest political couple the world has seen. Did the Sinn Fein MP ever think they'd end up together?

"I first heard of Ian Paisley at the time of the 1968 civil rights' marches in Derry. I remember his booming anti-Catholic, anti-nationalist speeches. I never thought he'd have the longevity or influence he's had. In the past, I've called him a sectarian bigot. I think he's called me worse, but I'll not repeat it!"

The "Butcher of the Bogside", the DUP labelled him. When McGuinness was last a minister, Paisley demanded he be thrown out of office and into jail. It won't be a love-in when they're in government, but neither will it be a row a day: "We'd a two-hour meeting last week and it was very positive, very courteous, " says McGuinness.

"I still think Ian Paisley was a sectarian bigot.

There's a lot in his past I dislike . . . I'd be a hypocrite to claim otherwise. But he has his own view of the world and he's stood by that. You can admire people for their principles even if you disagree with them.

"The DUP took a momentous decision to enter government with Sinn Fein and that's had an enormous impact on me and the people I represent. I don't believe Ian Paisley has gone into government to walk out of it. He's there to make it work."

'I'm not Ian Paisley's deputy' McGuinness has an easy, engaging manner that Paisley just might take to. He seems warmer and more down to earth than Gerry Adams. In the last Executive, he charmed even initially hostile Protestant civil servants. "Call me Martin, " he declared when other cabinet colleagues insisted on 'minister'.

So how does the former Bogside boy commander feel about becoming the second most important man in the North? "I'm jointly with Ian Paisley . . .

and it's you who have used the word . . . one of the two most 'important' men in the North. I was described on Waterford radio as 'joint first minister'.

"I'm not Ian Paisley's deputy. I don't see myself as anyone's second-in-command." How does he address the DUP leader? "I call him Ian. If he asked me to call him 'Dr' or 'First Minister Paisley' I would. He calls me 'deputy' . . . but in an endearing way!"

Both are family men, both like the simple things in life. Does McGuinness see similarities? "Well, I'm not quite as religious as Ian!"

He has rarely drunk alcohol since 1972. "Martin stopped because he was a lunatic on the whiskey, " a friend says.

"I've a glass of wine at Christmas dinner, but never more than two, " declares McGuinness. "I'd rather sit in the house with a mug of tea."

He loves Paris though: "I took my seven-yearold grandson there last year when Derry City played Paris St Germain. As we crossed the square outside Notre Dame, I thought, 'This is the first time I've been out of Ireland for myself.' All the other times, I was travelling for Sinn Fein."

'I'm blessed to do this job' He lives in an ordinary terrace in the Bogside with his wife Bernie who owns a local cafe. As deputy first minister, he'll make a 170-mile daily round-trip commute, rather than stay in Belfast during the week. "I strongly believe in going home every night. I rise at 6am. I'm blessed to do this job. Unionists and nationalists, loyalists and republicans, want this to work. I'll bust a gut to make it happen. I can survive on very little sleep." Like Margaret Thatcher? "I'm not like Mrs Thatcher in any way."

McGuinness undoubtedly has changed. "We don't believe winning elections will bring freedom . . . it will be the cutting edge of the IRA, " he said in 1985. As Derry OC, he said civilian casualties were inevitable: "We have always given ample warnings. Anybody hurt was hurt through their own fault: being too nosy, sticking around the place where the bomb was after they were told to get clear."

The greatest criticism McGuinness now faces is from some ex-IRA comrades who believe he has jettisoned republican principles for power: "My mother was from Donegal. I spent childhood summers there in a small thatched cottage. I'd have tears in my eyes going back to the city. I never understood why Donegal was divided from Derry.

I didn't accept the partition of this island then, and I still don't."

He speaks of the possibilities of the NorthSouth institutions and how working every day with nationalists at Stormont will ease unionists' suspicions and help persuade them about Irish unity.

"I remember Mitchel McLaughlin saying in 1994, 'This could take five years.' I naively thought the euphoria of the IRA ceasefire would apply all sorts of forces, that there'd be striking while the iron was hot."

Thirteen years later though, a credible Sinn Fein roadmap to Irish unity isn't apparent but the vast majority of Northern nationalists seem content with that. MI5's new �100m super-station outside Belfast hardly fulfils 'Brits out' either. "MI5 are everywhere . . . in Dublin, Galway, Paris, Belfast and New York, " says McGuinness.

"My project is to get them out as quickly as I can.

Fidel Castro has faced the same situation with Guantanamo Bay. The American military have a base in Cuba deeply resented by Cubans."

If republican dissidents attacked MI5's base would he condemn them and pass any information he had to police? He declines a straight yes-or-no answer. He isn't "into the politics of condemnation" but wants "an end to conflict, violence and death".

Last month's election showed republicans who oppose Sinn Fein are a minority, he says. "I'd defend to the last their right to disagree with us, but to try to resume a war that's over is a huge mistake and a great disservice to republican Ireland. "The track record of these groups is abysmal. In 21 years, the Continuity IRA hasn't fired a shot at a British soldier. Life moves on, things change. We've one of the most successful peace processes in the world.

"The Continuity IRA and the Real IRA have no right to risk the lives of our young people. The IRA fought a bitter conflict with the RUC and the British. They never militarily defeated the IRA and the IRA were never going to force every last British soldier down the Lagan or Foyle."

Landing the Big Man At 57, McGuinness looks well for his years: "At a dinner in Boston, a young Chinese woman came up and asked, 'Are you David Letterman?'

I said 'No, I'm Martin McGuinness but a lot of people in Ireland think I look like Art Garfunkel.'

I only wish I could sing like him!"

Relaxation is watching wildlife documentaries and Match of the Day. "I've supported Manchester United since I was eight and remember the Munich air crash, " he says. (A civil service official sighs heavily. ) But his great passion is fishing. "I like fishing alone in the dark. Some people are afraid of cows moving in the fields or foxes beside the river but I love it." He finds sea trout the biggest challenge: "They're real fighters. They've fantastic eyesight. They can see even a tiny fleck of silver on the fly." What's the biggest fish he's ever landed? "I know where this is going!" he says and smiles. "You mean Ian Paisley?" I don't, but he's laughing.