Alan Johnson: Labour's safe pair of hands drops out of political limelight

So even despite a tough start to life as Shadow Chancellor – where he had been a surprise appointment following Ed Miliband's win in the leadership contest – the news yesterday that he was quitting stunned Westminster.

The Hull West and Hessle MP had told Mr Miliband of his intention to quit several days ago, explaining the "personal reasons" which had brought him to the decision but the Labour leader had sought to persuade him to change his mind.

When that failed, he was left to finish off the details of his reshuffle on a visit to Wolverhampton Wanderers' Molineux stadium yesterday, before the news was announced at 5pm.

It marks the end of an impressive front-bench career for a man popular with his colleagues and respected by opponents.

Parachuted in as Labour's candidate in the Hull West and Hessle seat shortly before the 1997 election, the Londoner's charm quickly won over the locals.

Even as he rose up the Government ranks, he continued campaigning on behalf of trawlermen as they finally won compensation, and made a formidable cross-party force with Tory David Davis to lobby for jobs at BAE Systems in Brough.

The easy manner and intelligence of the postman who was orphaned and left school at 15 was teamed with sharp political skills honed during his rise up the Communication Workers Union – of which he became the leader – and he soon climbed the Ministerial ladder.

As Higher Education Minister he was responsible for pushing through tuition fees – which explained his later opposition to Mr Miliband's proposed Graduate Tax – before getting his first Cabinet job in 2004 as Work and Pensions Secretary after Andrew Smith resigned.

Over the next six years he was relied on by Tony Blair and Gordon Brown as someone to turn to in a tricky situation. As Health Secretary he eased relations with NHS staff infuriated by his predecessor Patricia Hewitt, and he even managed to leave the notoriously problematic Home Office without too many scars.

His failed deputy leadership bid in 2007 did little to diminish his popularity, with his ability to "speak human", a valuable asset for Labour to contrast to Mr Brown's problems communicating to voters.

He was regularly touted as a stop-gap Prime Minister when plotters sought to oust the premier, and while friends admitted he would have stepped in if the party needed him to, he always remained loyal.

But when Labour lost the election, questions were raised over the Big Beast's appetite for a demanding job, not least given his support for Ed's brother David for the leadership and his criticism of the younger Miliband.

His appointment as Shadow Chancellor was as much a surprise to him as to commentators, a political decision by Mr Miliband to keep Ed Balls from his desired position and attempt to stamp on suggestions that he would lead the party in a lurch to the Left.

His off-the-cuff joke that one of his first jobs would be to buy a primer of economics because of his lack of experience in the field became a millstone around his neck. It fed into a narrative that at a time when the country was emerging from economic crisis, Labour's most important brief was occupied by a student in the field rather than an expert.

Refusing to take questions after his first speech did not impress. Then two weeks ago he was floored in a television interview when he was unable to answer a question about the rate of National Insurance contributions.

The Tories seized on the blunders mercilessly. In truth he would surely have been better suited to a constitutional reform role shadowing Nick Clegg, which he cherished.

But for Mr Miliband, appointing Mr Johnson was such a big call it was vital to make it work. When Mr Johnson told him he wanted to quit, he was desperate to make him change his mind, insisting it was not a matter over which he had to resign.

By Wednesday, though, it was clear his persuasive powers would not be enough. The following day he offered Mr Balls the job.

Unsurprisingly, the man who spent years at Mr Brown's side in the Treasury was happy to accept.

The rest of the mini-reshuffle was completed yesterday in Wolverhampton, the audience at a question and answer session in a suite in Molineux unaware of the drama unfolding around them.

Mr Johnson's departure may end the jibes over an economic novice, but Mr Miliband's leadership has been dealt a blow. Observers will now be looking for any signs of cracks between him and Mr Balls, a man who fought him in the leadership contest and was senior to him in the Treasury during the Blair era.

Life and times of Hull MP

Born: London, 1950

Childhood: Orphaned at the age of 12 and brought up by his older sister.

Education: Sloane Grammar School in Chelsea. Left at 15.

early Career: Became a postman and worked his way up the Union of Communication Workers, becoming its youngest leader.

Political career: Became MP for Hull West and Hessle in 1997, joining Cabinet in 2004. Held Cabinet jobs for Work and Pensions, Trade and Industry, Education, Health and then Home Secretary. Failed to become Labour deputy leader in 2007. Became Shadow Chancellor after 2010 election.

Family: Fiercely guards private life. Has been married twice.