A cache of documents from the heart of the former Labour government has shone a light on Ed Miliband and Ed Balls's roles in Gordon Brown's plot to take over the leadership from Tony Blair.
The papers include letters exchanged between Blair and Brown which show them haggling over the terms for a handover of 10 Downing Street.
And they suggest that the Brown camp was planning for the change of power within weeks of the 2005 general election, with key roles in the process for Mr Miliband, Mr Balls and Douglas Alexander - now Labour's leader, shadow chancellor and shadow foreign secretary.
Labour sought to shrug off the significance of the papers which have been obtained by the Daily Telegraph. A senior Labour source said: "This is ancient history. We are a party looking to the future."
The files show how Mr Blair wrote to Mr Brown in February 2006, accepting that "you (understandably) want me to go now", but saying that care must be taken to ensure the new leader is seen as "the candidate of continuity and change".
This would require a "clear demonstration" to the public that Mr Blair, as the embodiment of New Labour, was "working hand in hand with the successor".
Suggesting a deal under which he would leave in summer 2007, Mr Blair said that in return he would need "full help and co-operation" on key reforms to the NHS, schools, the respect agenda, welfare and energy.
And he warned: "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."
On a copy of the letter he passed to Mr Balls, Mr Brown scribbled the words "shallow", "inconsistent" and "muddled".
And he responded with a document, which he intended Mr Blair to sign, setting out a deal under which Mr Brown would be put in charge of a number of future policy groups and would "set out with my full support and that of my team the agenda for beyond 2007 and for the next Parliament".
A set of memos from Mr Brown - littered with spelling mistakes and in block capitals - show how he tried to seize the agenda and prepare for a general election battle with David Cameron through a series of tours, speeches and books.
One memo sent to his key aide Sue Nye and Mr Balls in 2005 said that they needed to draw up a plan for "both election and inauguration" as Labour leader, identifying supporters and producing a campaign plan and a "narrative" for Mr Brown's elevation to Number 10.
Stressing the need to tell voters "the difference between one regime and the next", the memo sets out the message that "this is a government not a presidency... restoration of constitution and of trust" and the need to "redefine politics from spin/calculation/manoeuvre".
Mr Miliband was given the task of showing how Mr Brown's politics were defined by "third world idealism, environmental action, community spirit and an ethos of public service", rather than spin.
Other documents include internal polling evidence suggesting that voters saw Mr Brown as being "dour" but "robust" like a Volvo, while his expected rival at the general election Mr Cameron was seen as a more exciting "sports car" or "BMW