Five crucial questions that the Number 10 dossier leaves unanswered

Q. Why did Downing Street raise the stakes by taking the case to the PCC?

The dossier makes it clear that Tony Blair was furious when informed of the original and subsequent articles, but does not reveal why Number 10 didn't just issue a short rebuttal including the vital evidence that it was working on a 1994 set of guidelines. It should have known that using the PCC would raise a potential conflict with Black Rod's office. It should also have known a conversation conducted on two mobile phones would not be recorded, unlike land line calls from Downing Street. With no record, it would always be open to interpretation. Many suspect Alastair Campbell's own desire for revenge against old foes such as Peter Oborne and The Mail on Sunday may have played a part.

Q. Was Black Rod himself the source of any of the stories?

Stephen Glover claimed in The Spectator this week that the source for The Mail on Sunday story was "rock solid". "It was, in fact, Black Rod," he wrote. This was the first time in the affair anyone had named Sir Michael Willcocks as a source. When questioned yesterday by The Independent, Black Rod's information officer said Sir Michael did not want to comment and considered the matter closed. She did not deny Mr Glover's claim.

Q. What exactly is in Black Rod's "killer" memo? And will it ever surface?

Sir Michael is likely to have included an unvarnished account of Ms Sumner's tone and remarks to him. It almost certainly refers to a Downing Street detective informing him that Mr Blair was considering walking instead of driving to Westminster Hall. Speculation varied last night at Westminster as to whether the memo would be published by The Mail on Sunday this weekend.

Q. How precisely did Clare Sumner "express surprise" to Black Rod on hearing his rival version of the PM's role?

This is perhaps the key to the allegation that Downing Street tried to "muscle in" on the funeral. Ms Sumner's note states: "I said 'absolutely fine' and expressed surprise that people had different guidance given the event had been planned for such a long time but not to worry." However, her account does not explicitly set out the tone or exact wording of these remarks.

Q. Why didn't Black Rod's office or Buckingham Palace inform Downing Street of the changed guidance on the lying-in-state?

This is a real mystery. It may be that the 2001 detailed planning note simply forgot to mention the PM's role. All Buckingham Palace would say yesterday was: "During the length of the Queen Mother's life and towards the end of it, obviously revisions were constantly made to the plans as things changed."

Just as puzzling is why the PM and other party leaders' roles were downgraded from the 1994 guidance. Was Buckingham Palace so upset by Mr Blair's involvement in the aftermath of Princess Diana's death that it wanted to pull the PM down a peg or two?