Former News of the World editor Andy Coulson is to become the Conservative Party's Director of Communications.
Andy Coulson joins the Tories at a crucial time
Mr Coulson quit his job with the tabloid after one of his reporters was jailed for plotting to intercept phone messages left for royal aides.
The new job with the Tories will be a key one as David Cameron prepares to take on incoming PM Gordon Brown.
Meanwhile it emerged that Mr Brown's long time aide, Michael Ellam, will be his official spokesman in Number 10.
Mr Ellam, who worked for Ken Clarke before spending the last ten years working for Mr Brown at the Treasury, will handle the daily lobby briefings when Mr Brown succeeds Mr Blair.
As well as editing the News of the World, Mr Coulson, 39, is also well known for his past stint as editor of The Sun's Bizarre pop gossip column.
Mr Cameron said: "Andy is a hugely experienced journalist. I am delighted that he has agreed to join my team.
"Andy will make a formidable contribution as a senior member of my team in building the most effective strategy and operation to win the next general election. I look forward very much to working with him".
A Tory spokesman said Mr Coulson would give the Conservative press operation the extra "horsepower" it needed in the run up to the next general election.
"A lot of Andy's job will involve being in day-to-day contact with editors and senior commentators and dealing with long-term strategy," he added.
"We are not looking for an Alastair Campbell figure - his reliance on spin and aggressive media management has been discredited.
"But we are looking for more horsepower and we are delighted that Andy will be playing a key role in David Cameron's top team."
He said George Eustice would continue to be Mr Cameron's personal press secretary.
He denied Mr Coulson's job would involve building bridges with the Tory-supporting newspapers and columnists who have launched scathing attacks on Mr Cameron's education policy in recent weeks.
"This has nothing to do with the controversy over grammar schools," he said.
Mr Coulson quit as News of the World editor in January on the day Clive Goodman, the paper's former royal editor, was jailed for four months for illegal phone tapping.
A Tory spokesman said the party was satisfied Mr Coulson was not to blame for the scandal after he was cleared by a Press Complaints Commission investigation.
The PCC found no evidence that Mr Coulson or anyone else at the paper was aware of Goodman's illegal activities.
A close friend of former Daily Mirror editor Piers Morgan, Mr Coulson started out as a reporter on the Basildon Evening Echo.
He rose rapidly through the News International ranks, editing The Sun newspaper's Bizarre gossip column and, in 2003, succeeding Rebekah Wade as editor of the News of the World.
His reign saw a string of old-fashioned tabloid exclusives, lifting the lid on the private lives of David Beckham, David Blunkett, Sven Goran Eriksson.
Commenting on his latest role, Mr Coulson said: "I am delighted to be joining David Cameron's team and I look forward to helping the Conservative Party to return to Government under his leadership."