How the former secretary of the repatriation committee of the notorious Monday Club became a Tory Speaker elected on almost entirely Labour support is testament to years of work by the MP from Buckinghamshire and the deep cynicism of his backers.

Few dispute the fervour with which John Bercow wanted to succeed Michael Martin, a campaign that he has been waging by stealth for months. Indeed, a burning ambition sustained him through a vicious “anti-Bercow” campaign by Tory MPs and parts of the media, much of which had the tacit support of David Cameron, his erstwhile parliamentary tennis partner.

Yet by 11am yesterday morning it was clear that his support on the Labour benches was making him unstoppable, pushing him to victory by 52 votes — a wider margin than some of Gordon Brown’s critical votes.

Mr Bercow did not escape criticism over his parliamentary expenses, paying to Revenue & Customs the £6,500 that he avoided in capital gains tax after “flipping” his second-home allowance.

He is the first Jewish Speaker and at 46, the youngest since Charles Shaw-Lefevre, Viscount Eversley, who was 45 on election in 1839.

The result yesterday is a tribute to the organising power of Martin Salter, the Labour MP for Reading — Mr Bercow’s neighbouring constituency — and serial rebel and their desire to punish the Tories for ousting Mr Martin. But who exactly did he persuade them to sign up for?

At first he looks like an unlikely candidate for widespread Labour support. The son of a taxi driver who went to a comprehensive school, in his teenage years he was an exceptional tennis player destined for Wimbledon until his chances were dashed by glandular fever. From this point he became more political. At 18, inspired by the speeches of Enoch Powell and concerned about the impact of mass immigration, he joined the Monday Club — a right-wing Conservative pressure group founded in 1970 that was notable for having promoted a policy of voluntary, or assisted, repatriation for non-white immigrants.

At the University of Essex, he fought battles with the Left and became national chairman of the Federation of Conservative Students. It was the era of “hang Nelson Mandela” T-shirts in the Tory party — he says he never wore one — and one that he would rather forget.

He went into banking before joining the Major Government in its final days as a special adviser, first to Jonathan Aitken — before the minister resigned to fight a libel suit with The Guardian — and then Virginia Bottomley.

In 1997, on his third attempt, he became an MP, with a smooth ascent through the opposition ranks, pausing only once to declare that he did not consider himself ruthless enough to reach the top of politics.

Then, in 2002, came the event that defined his political career — his resignation from the Tory front bench in protest at Iain Duncan Smith’s decision to impose a three-line whip on MPs in the debate on gay adoption. Although he was brought back by Michael Howard, this event proved seminal as he “came out” as a moderate Conservative.

“It’s true that I’ve got the zeal of the convert but that doesn’t mean that the conversion is any less genuine or that the need for constant repetition of the message is any less great,” he said days after the resignation.

“It was extremely ill judged to prescribe how Tory members should vote on that subject. It defies common sense that there can be only one Conservative view on this subject.”

From then on, he was treated differently by Tory MPs and, as if to underline his ideological switch, married a Labour supporter, Sally Illman, who watched his triumph yesterday. “He has been on a journey that makes his one-time hero Michael Portillo seem like a mere day-tripper,” one prominent Conservative said.

In many ways, Mr Bercow was able to see a vision of Cameronian Conservatism before Cameron arrived. “There is still a challenge to get it across to existing Conservatives that if we are to win we need to change. It’s not good enough to say we’ve always been right, we’re still right, we have nothing to learn, all we’ve got to do is wait for the public to say we got it all wrong in 1997,” he said in 2002.

Mr Bercow said during the Tory leadership election that Mr Cameron’s Eton background made him wrong for the job. He backed Ken Clarke.

It was then that he began to reach out to the other side of the House more obviously. When Gordon Brown became Prime Minister in 2007, there were rumours that he would defect. He preferred instead to lead an investigation into special needs children on behalf of Mr Brown, something that sealed the divorce with the Tories in the view of many colleagues.

Mr Bercow then began to immerse himself in parliamentary reform. He joined the Hansard Society and took a close interest in parliamentary structures, developing the foundations of his manifesto for Speaker very early.

Yesterday he pledged to strengthen the Commons and take on the executive, saying “the case for strengthening backbenchers, to revive Parliament as a whole, is incontrovertible”.

He also campaigned on one of the most cringeworthy — but seemingly effective — slogans of modern political history. “I would be comfortable to be both a Speaker and a listener.”

If he sticks to his word, there is little chance that the Tories, furious at his election, will try to deselect him. Any sign that the ideological journey that brought him here is still shaping his views and he may be the shortest-lived Speaker in recent history.

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