[cyncooper]

And no-one had checked in the intervening month?

I asked "why" anyone would have done that.

I see you have no answer.

It is an opinion memo. Are you demanding leaders track down the authors of opinion memos in order to intimidate, harrass and force a recantation or what?

[Canard]

My answer is that, if there was any doubt as to the existence of the memo as reported, that would have been the first focus of the internal investigation that undoubtedly took place in Downing Street after the story was printed.

I suggest you have a look into the David Kelly/BBC affair to see how Downing Street reacts when journalists make allegations against them using dubious evidence and compare to the reaction in this case.