Alan Johnson: Coming man

One of Westminster's best kept secrets is that the new Home Secretary, Alan Johnson, is a closet intellectual. He will deny it, of course. One of his great political assets is a back story that is the envy of every university educated Labour MP. He left school early, without an O level, and now holds one of the great offices of state. Yesterday, he was confirmed as the runaway bookies' favourite to be the next labour Prime Minister.

But if you were to travel with him by train to London from his parliamentary seat in Hull, and if you were to utter the words "success so huge and wholly farcical ... like a happy funeral", other people might think you were making an oddly phrased comment on the current state of the Labour government. But Johnson would know at once that you are quoting from The Whitsun Weddings, by Philip Larkin, which was inspired by just such a train journey.

It is a favourite work by one of Johnson's favourite poets. It is curious that he should admire Larkin so much, because the poet's take on life could ben very gloomy. There is a line that Johnson quoted in a speech to the National Family Parenting Institute, that that "man hands on misery to man. It deepens like a coastal shelf. ..."

That observation just does not apply in Johnson's case. At the start, his life was strewn with difficulties. He could have emerged from them with a chip on his shoulder, resentful of people who had enjoyed better fortune, or feeling inferior to those with better qualifications. But in his case, the misery emphatically was not handed on.

And although he left school early, he is actually one of the best educated ministers in the government – albeit self-educated. When he was a postman in Slough, he was to be seen in his break, at the wheel of his van, devouring a DH Lawrence novel, or something by Jack London, possibly even a political essay by Gramsci.

But his self-education is somewhat eclectic. He used to poke fun at Tony Blair's taste in music, from the viewpoint of a true rock connoisseur, whose son, Jamie, works in the industry as an engineer for Paul Weller and others, who can talk about the chord sequences in Lennon-McCartney songs, plays the guitar, and has kept abreast of the times. Try saying the words "first time, I did it for the hell of it" to Johnson, and he will come back at you with a complete history of the Super Furry Animals from their formation. He has said that he would rather be the Welsh rock band's lead singer than Prime Minister.

Simon Lancaster, a rare example of a career civil servant without a university degree, worked with Johnson in a succession of government departments, but was obliged to confess one day that he had never heard of the singer Richard Thompson. The following morning, there was a copy of Thompson's 1991 album Rumor and Sigh on his desk, a gift from the Secretary of State.

Johnson's father, a painter and decorator, walked out on the family when he was eight. His mother, a cleaner, later died, and he and his elder sister were apparently destined for a Barnardo's home, but a child welfare officer was so impressed by the maturity of his 15-year-old sister that brother and sister were allotted a council flat in Battersea in south London.

He went to Sloane Grammar School across the river Thames in Chelsea, and left at 15 without any O levels. His first job was stacking shelves at Tesco, but he walked out because the bosses would not allow him a lunch break. At the age of 18, already married with two children, he became a postman in Slough. One of the houses on his round was Dorneywood, the fine grace-and-favour mansion that is normally allocated to one of the most senior cabinet ministers, which can sometimes mean the Home Secretary.

His road into politics was through the postal workers' union. The post office strike of 1971, which coincided with the arrival of his third child, gave him his first taste of industrial struggle. In 1987, after 19 years' delivering letters, he became a full-time union official. In 1993, he became general secretary of what was then the Union of Communication Workers, with a seat on Labour's National Executive.

A year later, Tony Blair became first leader of the Labour Party who could operate independently of the trade union block vote. This freedom allowed him to keep union bosses at a distance. But Johnson was an exception. He was almost the only union general secretary to support Blair's campaign to rewrite the party constitution, defying left-wing members of his own union executive. As the 1997 general election loomed, the Labour MP for Hull West, Stuart Randall, was persuaded to accept a peerage, and Johnson was eased into his seat.

Having brought him into Parliament, Blair had no intention of leaving his favourite trade unionist languishing on the backbenches. Almost immediately, Johnson was given an unpaid role as a parliamentary aid to Dawn Primarolo, a treasury minister, and after only two years in the Commons he was on the ministerial ladder as a junior minister at what was then the Department of Trade and Industry.

In 2003, he was moved to the Department of Education to help the new Secretary, Charles Clarke, push through highly contentious legislation that introduced variable top-up fees for university students, which got through the Commons by just three votes, the narrowest victory this Labour government has ever had.

Johnson's famous joke about this skin-of-the-teeth victory was that it was achieved through a charm offensive – "I was charming, and he was offensive." It helped that Johnson had never been to university himself, because it made him immune from the accusation that ministers were denying young students privileges that they had once enjoyed.

After that success, no one doubted that Johnson was destined for the Cabinet. Since 2004, he has been successively in charge of Work and Pensions, then Trade and Industry, Education and Skills, the Health department, and now the Home Office.

One of the skills he has displayed in his steady rise is an ability to attract loyalty from officials who have worked for him. Simon Lancaster was a junior civil servant, earning less than £18,000 a year, when he was appointed Johnson's private secretary 10 years ago.

"Different ministers have different styles," Lancaster said. "You get some ministers who are very aggressive and naturally hostile to civil servants. Alan was very much the kind you made you feel you are part of the team, and he will defend you to the death. When I was very junior, I was involved in a cock-up over his diary, involving someone very senior, who complained about me to the Permanent Secretary. When Alan found out he went absolutely potty at the guy for complaining. He will stick always up for you.

"There were two occasions when I was working as his speech writer, doing something like 14 hours a day and beginning to feel 'Oh my god, why am I doing this?' Both times, I had an envelope addressed to Simon Lancaster personally with a little note from him saying, 'You're the best speechwriter in Whitehall' or something like that. It just gave me that extra buzz to keep going.

"At the Department of Trade and Industry there was a legendary tea lady named Rita, who would burst into ministerial meetings rattling her tea trolley and say, 'How are you minister?' She had been at the department for about 30 years, working for Conservatives and Labour alike. When she retired, Alan took her for tea in the House of Commons. He was the Secretary of State, so you can imagine how much that meant to her. He is a genuine good guy, who attracts loyalty – emotional loyalty, not tribal loyalty."

Yet there is a mystery about Johnson, which even those who have worked closely cannot answer. Just how ambitious is he? Other ministers who find themselves tipped as the next Prime Minister have let the pressure get to them and have done something foolish. Johnson has not put a foot wrong, as if it is all the same to him what people say about his future.

In his ministerial career, he has shown occasional flashes of ruthlessness, but generally he is a man who likes to get on with everyone. Whether he really wants the pressure and hostility that he would encounter as Prime Minister is open to doubt. His friends say that if the job is open, he will go after it, but if it passes him by, he will not let the disappointment sour his life.

A life in brief

Born: in London, 17 May 1950.

Family: Orphaned at the age of 12, he was raised by his elder sister in a council flat. Married twice and has four children.

Early life: He attended Sloane Grammar School in Chelsea and left at 15 to stack shelves in Tesco.

Career: After working as a postman, he joined the Union of Communication Workers and was a member of Labour's National Executive Committee. He was elected to Parliament in 1997 in the safe Labour seat of Hull West and Hessle when the previous incumbent, Stuart Randall, stood down suddenly. Mr Johnson got his first ministerial role in the Department of Trade and Industry in 1999. He entered the Cabinet in 2004 as Secretary of State for Work and Pensions. The role of Home Secretary is his fifth Cabinet position.

He says: "I continue to believe Gordon Brown is the best man for the job."

They say: "Alan was very much the kind you made you feel you are part of the team, and he will defend you to the death." Simon Lancaster, Mr Johnson's former private secretary.