Downing Street has denied any connection with an internal memo that apparently admits the Government is seen as a "shambles".
The Mail on Sunday reports that the document was prepared for Tony Blair by senior aides, and gives a bleak assessment of Labour's situation.
It expresses concern that the party is viewed as riven by "internal conflicts" and lacking "grip and competence on vital issues".
The memo also apparently warns that the position of Mr Blair's likely successor, Chancellor Gordon Brown, is "eroding" against David Cameron's "increasingly acceptable" Tories.
It is said to insist that the party is running out of time to avoid electoral disaster.
A spokesman for the Prime Minister said: "This is not a Downing Street memo, it was not written by any of the Prime Minister's staff and it most certainly does not reflect his views."
Downing Street sources also insisted the memo had not been prepared by any of Mr Blair's special advisers or other Labour Party-funded staff in his personal office.
