Leak of advice designed to damage Labour's election campaign

The leaking of the Attorney General's secret advice to Tony Blair was clearly targeted to inflict maximum damage and blow Labour's election campaign off course. Lord Goldsmith's conclusions were copied in longhand before being faxed to avoid any possibility of a leak inquiry tracking down the source.

The document caused consternation inside the BBC when it arrived on the desk of an executive. Attempts were made by a BBC correspondent to verify the authenticity of the fax.

With the wounds still fresh over the Andrew Gilligan claims that triggered the Hutton inquiry and led to the resignations of the director general and chairman of the BBC last year, the corporation's senior staff did not wish to fall foul of a hoax. Copies were sent toThe Guardian and to Channel 4 News. To the irritation of BBC journalists, Channel 4 scooped the BBC and ran the story at 7pm, 45 minutes ahead of a report on BBC News 24. Kevin Marsh, the editor of the BBC Radio 4 Today programme, said yesterday the matter should have been handled differently. "The document had been in the BBC since 4pm so to learn about it on Channel 4 was a shock," he said. "The BBC is a vast organisation and what came in was a fax of a re-typed up original document. It came in somewhere centrally and it was checked out centrally for authenticity and whether it was saying anything significant. Obviously they haven't been able to do all that before Channel 4 News." It is understood that Channel 4 received its copy before the BBC but Mr Marsh said: "Had that come into a [BBC] programme it would have been dealt with differently. I had a word with our deputy director general [Mark Byford] about it." Some sources suggested the document had been leaked to Mr Byford's office, which might suggest it came from a high-level government or civil service source. This was not confirmed by the BBC.

At Conservative campaign headquarters, Guy Black in the leader's office took a call from Channel 4 at 6.30pm asking for Michael Howard, the Tory leader, to go on air. Mr Howard, a Liverpool supporter, was on his way to Stamford Bridge for the Champions League match between Chelsea and Liverpool. He went on air at 7.50pm outside the ground, with the sound of the crowd in the background.

Over in the Labour campaign headquarters, the finger was being pointed at the Tories, noting the leak was co-ordinated - not something usually done by a disgruntled individual - and targeted for maximum effect. Alastair Campbell, Labour's campaign strategist, yesterday decided to kill the leak, and ministers ordered it to be published in full. It would have been necessary anyway under the Freedom of Information Act, once the conclusions had been put in the public domain. Downing Street said no inquiry had been announced. If one is started, it will have to investigate those who had the documents. It is a short list. Few in the Cabinet had seen it, until yesterday. Patricia Hewitt, the Trade Secretary, said she read it on Channel 4's website.