The strange case of Benji the Binman, Hague's friends at Wapping and the whiff of a July plot

Philip Gould has pinned a handwritten note next to the dustbin at his north London home. "F*** Off Benji the Binman", it says.

Philip Gould has pinned a handwritten note next to the dustbin at his north London home. "F*** Off Benji the Binman", it says.

The note reveals that Mr Gould, Tony Blair's pollster and one of his closest aides, believes that the man who rifles through people's bins holds the key to the flood of damaging leaked memos that has destabilised the Government.

Mr Gould said yesterday: "Ever since my memos started being leaked to the press, I had suspected 'dirty tricks' rather than a mole."

Downing Street staffers, while furious about the leaks, are sleeping slightly more easily, since they are no longer convinced there is a mole in their midst intent on inflicting maximum damage to the Government. Instead, Blair aides now believe the explanation is a triangle involving the source who obtained the seven leaked memos, Rupert Murdoch's News International empire and the Conservative Party.

But who is the original source? No one knows yet. Special Branch officers are helping Sir Richard Wilson, the Cabinet Secretary, try to find out.

One theory is that it is Benjamin Pell, an obsessive 36-year-old who drives around London emptying people's bins into black plastic bags. He preys on the well-known and rich and has sold his booty to several newspapers, includingNews International's. All seven memos have surfaced in The Sunday Times, The Times or The Sun, all part of the group.

Mr Pell, who denies any involvement in the leaks, was fined £20 in London in November on five counts of "stealing documentary waste". Police who found 200,000 documents in his garden shed also discovered a £2,500 cheque from News International.

The prospect of a destructive mole burrowing away at the heart of the Government is receding because of leak number four (see panel), in which Mr Gould said the New Labour brand had been "badly contaminated." The version that appeared in The Times and The Sun was only a draft penned by Mr Gould, who never sent it to Mr Blair. So it could not have been leaked by someone at Number 10.

Mr Gould has told the leak inquiry that the memo "differed in many significant respects from any document that was ultimately sent to colleagues". He said yesterday: "The document that was published in the press was taken from my computer, or my home, or my dustbin. Whatever the exact details, I am in no doubt that the law was broken to obtain this and other documents."

Mr Gould believes "Benji" may have obtained some of the memos from his dustbin. But this does not explain leak number three, in which Mr Blair admitted he and his Government were seen as "out of touch with gut British instincts". This was sent to Mr Gould, but kept under lock and key at his office in the Express Newspapers building in London.

Downing Street is now convinced there is a conspiracy between News International and Conservative Central Office. The timing of the disclosures has without doubt been to the benefit of the Tories. Two bombshells have been primed to go off to overshadow important policy announcements - the three-year spending programme by Gordon Brown last week, and the national plan for the NHS yesterday.

William Hague denied yesterday that the Tories were behind the leaks, saying his party was not on the "copy list" for the memos. But some senior Tories cannot resist a wry smile. "This is Amanda Platell's finest hour," one Tory source let slip.

Blair aides suspect that Ms Platell, the Tories' head of media, is masterminding the leaks operation. She is a close friend of Andrew Pierce, the Times journalist who disclosed four of the seven memos. When she was sacked as editor of The Sunday Express, he resigned in protest. Ironically, Mr Gould, a director of Express Newspapers, was a fan of Ms Platell.

One Downing Street theory is that all seven memos were part of a "job lot" obtained by the Insight team at The Sunday Times, which revealed the first two. The team's methods were called into question after it disclosed the tax affairs of Lord Levy, a Labour Party donor.

According to this thesis, things were "getting too hot" for Insight, so the remaining documents were handed to a News International executive, who passed them on for simultaneous publication in The Times and The Sun. "It is very interesting that no leaks have appeared in the News of the World - the one Murdoch paper published the same day as The Sunday Times," said a Blair aide.

Mr Blair's allies claim errors are creeping in to the operation, and suspect the hand of Conservative Central Office. Yesterday The Times and The Sun suggested a memo by Mr Blairon Europe was written in December, but Downing Street insisted it was penned in April this year, at the same time as the other leaked memos.

The two papers also said a second memo was co-written by Mr Gould. But it was drafted entirely by Stan Greenberg, President Clinton's pollster and Mr Gould's business partner. Mr Gould said his name never appeared on any draft, and suspects the Tories of telling the two papers it was jointly written by him and Mr Greenberg to give it more impact.

The Blair camp admits that crucial pieces of the jigsaw are still missing. It does not know whether the memos went to the Tories or News International first. If they went to the Tories, why were they all handed to Murdoch papers rather than shared out to make it harder to allege a conspiracy?

One thing is for certain: someone is not telling the whole truth. In an editorial comment yesterday, The Times said it had not paid a penny for its material or been in league with people who search dustbins. "Such stories are a deliberate political smokescreen," the paper said. Perhaps Special Branch will soon reach a conclusion on whether that is right.