In it, he tells Taki that Nigella had always found him " toe-curlingly vile, and would have been aghast at having you as her valiant supporter."
And then he throws the floor open to his opponent, who is long known for possessing a black belt in karate - an ancient martial art Saatchi dismisses as "soppy geriatrics rolling around the floor in crisp white outfits".
Saatchi's own fights, he claims, "take place in cages, 20 feet square, unofficial little events with no gloves, no rules, and the loser being carried out, usually battered to bits. You will understand why I laughed out loud at your schoolyard boast that I should try throttling a real hard case like you."
Astonishingly, Taki appears to have accepted the dual - providing he's given at least 'three days' notice' to prepare, that is.
"I am willing to face him any time under cage-fighting non-rules, which will be a first for me," he replied.
And so, The Spectator offered to stage the event - a brawl to the bitter end in a specially erected cage in the garden of their Westminster office.
However, it seems Saatchi would need ample time for some pre-fight smack-talk, too.
"I suggest dinner with Taki and Fraser [Nelson, Spectator editor] can be referee," he emailed the London Evening Standard this morning.
- UK Independent