Andy Coulson: Tabloid hack who broke into Tories' inner circle

Andy Coulson was the stellar tabloid journalist who brought to David Cameron's team a killer instinct for what made news.

Three and half years after he was appointed as the Tories' chief spin doctor, however, he knew that he was becoming the news himself.

That had been Alastair Campbell's cardinal sin in taking on the media so vociferously as Tony Blair's press chief.

Mr Coulson, 43, sought to avoid comparisons with Mr Campbell - another former tabloid hack - by taking a much lower profile in Westminster as the Tory leader's head of communications.

But he could never shake off the explosive allegations against him from his time as editor of the News of the World.

Mr Coulson denies any knowledge of phone hacking by reporters under his editorship, but the story has only intensified since he entered Downing Street alongside Mr Cameron.

As he acknowledged in his resignation statement today: "I stand by what I've said about those events but when the spokesman needs a spokesman it's time to move on."

An Essex boy done good, Mr Coulson brought a unique perspective to the most senior levels of the Conservative Party.

In a team dominated by public school and Oxbridge graduates, Mr Coulson attended a state comprehensive and worked for a local paper - the Basildon Evening Echo - instead of going to university.

He did not even have a background in political journalism, instead following the showbiz route to the top of the News of the World via The Sun.

But his glittering tabloid career was left in tatters after his then royal editor Clive Goodman was jailed after pleading guilty to illegally intercepting phone messages from Clarence House.

Mr Coulson said he had "ultimate responsibility" for the scandal and apologised "unreservedly" to Princes William and Harry.

Only months later, in May 2007, Mr Coulson was unveiled as director of communications and planning with the Conservative Party.

Little more than a year earlier, the News of the World had published a front-page photograph it claimed showed George Osborne - now the Chancellor - and a prostitute with cocaine.

Mr Osborne said at the time the allegations were "completely untrue" and part of a "smear campaign", but he was said to have been central to the campaign to recruit Mr Coulson later.

Turned gamekeeper, Mr Coulson was credited with sharpening the Tories' message at a time when Mr Cameron was still seeking to establish himself as a credible alternative prime minister.

But the phone hacking scandal continued to rumble on in the background and took on a new significance when, after last year's general election, he became one of the most important figures in Number 10.

The scandal re-erupted with fresh claims about the extent of the phone hacking scandal - again fiercely denied by Mr Coulson and News International, the newspaper's owner.

But it was an issue that dogged not only Mr Coulson but the Prime Minister himself.

Only this week Mr Cameron was challenged about his press chief, with the Prime Minister saying he believed in giving people "a second chance".