Letters and files obtained by the Daily Telegraph reveal the key role played by current shadow chancellor Ed Balls in Gordon Brown's attempts to overthrow the then-prime minister.
The reports also allude to a wider group - including current Labour leader Ed Miliband and shadow foreign secretary Douglas Alexander - preparing the ground for the transition between Mr Blair and Mr Brown, starting within weeks of the 2005 general election. The move was dubbed Project Volvo.
The language of the memos Mr Brown sent Mr Balls and others is startling.
"This is a government not presidency," he wrote in the autumn.
"Restoration of constitution and of trust. Leadership that gets on with the job... Trust depends on proper relationship between executive legislature and civil service, Labour the champion of the constitution... Need to redefine politics from spin/calculation/manoeuvre... No presidentialism."
Later, he wrote to Mr Balls: "If we are to renew Labour, we will have to be as rigorous and brutal as we were in the creation of new Labour."
Mr Brown took to passing on highly confidential notes between Mr Blair and himself to Mr Balls, who was long considered his right-hand man, in the wake of the election.
By February 2006 Mr Blair was seeking to make a deal with Mr Brown to organise an orderly transition.
"You (understandably) want me to go now," Mr Blair wrote.
"You need to be the candidate of continuity and change. The second will be relatively easy to do. A different person is, by its nature, change.
"The first, however, rests on a smooth transition. Critical to that is not merely the absence of disunity in the handover; it is also the visible, clear demonstration that the person who most embodies NL [New Labour], ie: me, is working hand in hand with the successor."
The letter goes on to suggest several policy areas in which Mr Brown can take a front-stage role, including counter-terrorism and democratic renewal - an area he was to sieze on years later during his time in Number Ten.
In return, Mr Blair wanted cooperation on his main policy areas, including NHS reform, education and the 'respect' agenda.
"Whilst I remain PM, the final decision has to be mine; and that cannot provoke a breakdown. I will try, at all costs, to avoid disagreement, but there can't be stalemate if it happens," he warns.
The letter was then passed on to Mr Balls from Mr Brownb's office, with the then-chancellor scribbling the words "shallow", "inconsistent" and "muddled" on it.
A subsequent deal document, proposed by Mr Brown lay out the need for six-month, 12-month and two-year strategic plans, a role for him in future Cabinet reshuffles and his attendance at international meetings.
Mr Brown wrote: "I propose the following: across a wide range of areas you [Brown] are put in charge of future working groups beyond economic policy so that Labour with you leading is seen as party able to meet big challenges of future.
"You [Brown] will however set out with my full support and that of my team, the agenda for beyond 2007 and for the next parliament."
The deal fell apart, apparently because of Mr Blair's irritation with Mr Balls.
While the files mention Mr Miliband, Mr Balls is likely to be worst affected by the story, as it resuscitates the worst aspects of his reputation.
Known as a bruiser in parliament, the shadow chancellor's warm expression while speaking to the media is entirely at odds with the tough, plotting character alluded to in the files.
Reports this morning suggested that Cabinet secretary Sir Gus O'Donnell is set to order a leak inquiry into how his files were made public.
It is understood that the last time Mr Balls saw the handwritten notes they were on his desk at the Department of Education at the time of the general election.
Mr Balls then went on to fight the Labour leadership election, but his association with Mr Brown proved to be his undoing as Ed Miliband, seen by many Blairites as the acceptable face of Mr Brown's coterie, took the leadership.
Labour figures have tried to write off the story - which will continue to be published by the Telegraph as the month progresses - as ancient history, but with Mr Balls taking on an increasingly high profile role in Mr Miliband's party, it will be met with dismay behind closed doors.
A renewed media fixation with the tribal disruptions of New Labour runs against Mr Miliband's attempts to put the period behind him.