“The Boss is coming,” whispers a policeman urgently into his radio, back in Downing Street in April. Back then, Tony Blair still had two months of being the Boss to go. As of today, he’s the Boss till Wednesday.

“So Robert,” he says, striding to the Daimler, “looking forward to this?” Oh yeah, I say, this is going to be fun, how are you? “I’m absolutely knackered.” We had met during the 2005 election. “You’ve worn better than I have,” he says, in one of several references to the ageing process. “God,” he mutters at one point, signing a picture of himself, “is that what I used to look like?” We drive to RAF Northolt, then fly to Glasgow. Elections to the Scottish Parliament are eight days away.

Blair is still a vigorous man: good shape, goes to the gym three times a week, careful around the biscuits laid out wherever he goes. He has the stamina to engage Colonel Gaddafi at midnight when the rest of us, Libyans and Brits, are yawning uncontrollably. But up close the effects of ten years’ stress and not enough sleep are clear. He looked younger than 44 in 1997; he looks 54 now. “The thing about the job,” he says, “is its utter relentlessness. It never leaves you. Never. It is emotionally, physically and mentally draining.”

His hair is mostly grey, and thinning. He pats it down before public appearances, checks “is it all right?” with an aide. In private, he’s always reaching for his specs: “I’m as a blind as a bat.” His people are protective: no photos while he’s being made up or miked up for TV. When he’s tired, or angry, Blair’s expression can take on a vulpine quality.

Blair casts himself as EU president candidate

Speaking on French TV, Tony Blair sang the praises of the EU and sketched his agenda for its future, all in fluent French

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On the plane to Glasgow, however, Blair grins and chats, seems in a good mood, despite the opinion polls forecasting an SNP victory. Whatever the physical changes, emotionally he remains the untroubled character the British people fell for ten years ago. If the wing comes off this Dornier right now, I thought, of the 17 souls aboard, his would probably plunge to earth with the clearest conscience.

And he’d also believe he’d be going to a better place. One day, a book will analyse the impact of Blair’s faith on his premiership; it is already clear religion was central to two vital relationships. Ian Paisley decided to trust Blair once he realised he was serious about his faith. Shared Christianity cemented his alliance with George Bush. It also, I suspect, greatly aided his dealings with the Queen.

Blair, by the by, is keen to deny reports that Her Majesty and he don’t get on. “Complete nonsense,” he says. “Absolutely untrue. My relationship with the Queen is very open, very easy, very comfortable, and I’ve never had a bit of difficulty, not from the very beginning. Obviously when you’re a new Prime Minister, especially when she became Queen before you were born, you’re somewhat nervous of her. It’s got easier because we’ve got to know each other far better. She’s always been very good with me.”

Another salient point about Blair’s character is not so much what’s always said, that he’s a showman, a performer, an actor, but that he’s an optimist. An optimist almost to a fault. Early pictures show a sunny-natured child. “He’s the kind of person who always sees good in people,” one of his aides tells me. “It can be frustrating. During a reshuffle, some of us might say, ‘Get rid of so-and-so, he’s f****** useless,’ and he’ll say, ‘Oh, come on, he hasn’t been that bad.’” Blair doesn’t divide the world up into left and right, indeed he’s made an ideology out of not doing so. But optimist versus pessimist, that’s a meaningful dichotomy for him.

Back in Scotland in April, it being election time, Blair is wearing a red tie. It being a Wednesday, Prime Minister’s Questions just completed, he’s also sporting his lucky brogues. “I know it’s ridiculous, but I’ve worn them for every PMQs. I’ve actually had them for 18 years.” Over the weeks, Blair’s uniform is always the same. I thought he might do that chino/polo thing in Basra with the boys, but mercifully, no: same dark-blue suit, white shirt, stripey tie.

A motorcade takes us to a community centre in Rutherglen east of Glasgow. It is packed with the Labour faithful. Blair grins his way through a succession of 90-year-olds who still go to all their branch meetings. “How ya doin’ darlin’, you’re wearin’ well, wan’ a picture?” Many of his supposed flaws are myths, but this one, that he’s a chameleon, moderating his speech to suit the audience, this one, if flaw it is, is real. With captains of industry, he’s precise, Latinate, the hyper-fluent ex-barrister as opposed to a halting consonant swallower.

Tommy McAvoy, the local MP, introduces “Tony! Blair! Our! Labour! Prime! Minister!” Afterwards, Blair speaks to Billy from the Kirkintilloch Herald. Billy is a Sunderland fan. “Keano’s been great, hasn’t he?” says Blair. “Niall Quinn’s a good friend.” It’s no wonder Blair prefers the regional press to the “feral beast” of the nationals.

Blair spends a lot of time talking to journalists. He does not, however, read much of what we write. In the two months I shadowed him, from Glasgow in April to last Sunday in London, with Belfast, Baghdad and Jo’burg in between, I saw him reading a newspaper only three times. After the Champions’ League final, he studied the player ratings in The Times.

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