For the Avoidance of Doubt – I do not work for MI5

I am publishing this as a free-standing post because I feel it must be resolved properly, and want to be certain that the person involved is aware of the risks he runs.

Some days ago, in a response to my column of last Sunday ('This is no SuperCam'), a Mr 'Harold Stone' posted a comment. I should say here that some of his comment was edited for legal reasons but - according to the rules which operate here - his direct personal criticisms of me were not edited.  All may say what you like about me, provided it is true, or just hostile and abusive. Untruths, however, are not acceptable. The editing process also led to a delay in his words being published. But they were published.  This is what he said:
He first quoted what I had said  :'It occurs to me - though of course it isn't true - that if MI5 wanted to discredit any honest movement against mass immigration, the cleverest thing it could do would be to set up something called, say, the 'British Patriotic Party', and staff it with Jew-haters, racialists and Holocaust deniers.'

He then wrote: 'And it occurs to me – since of course it is perfectly true – that an MI5 anxious to ensure we continue to believe we live in a society which protects free speech would almost certainly staff newspapers with faux-conservative "assets" to lead people up blind alleys about the effectiveness of the party system, or oppose repatriation on "moral grounds" because the other deception they peddle, about the irrelevance of racial differences, allows them to insist that an Englishman can come from Tunbridge or Timbuktu. You'd scarcely be the first newspaper journalist to be run by the security services (think Ian Fleming and a score of others less well-known). Speaking as a racialist myself, that is to say one genuinely led by the facts, by observation, by reason and the lessons of history rather than pretending to be, I'd say it's how all security services operate to discredit truth-tellers. Trotsky ordered the cadres to ignore rational argument and to make truth-telling distasteful to people. Equalitarian dogma (disguised as Christianity?) could thereby pass itself off as 'authentic' conservatism which, because of its ideologically driven repudiation of biology, would fail to conserve a damned thing. Again I must ask if you know what a nation actually is Mr Hitchens, you who boast about your grasp of history, and wonder what on earth gives you the right to sneer at Cameron when you display not a shred of integrity yourself on this subject, since it's plain you know the truth deep down?'

Mr Stone is welcome to his opinions, much as I dislike them. But he appears to suggest that I am an employee or servant of the Security Service, engaging in systematic dishonesty on their behalf. He uses these pretty direct words: 'You'd scarcely be the first newspaper journalist to be run by the security services' and  'it occurs to me – since of course it is perfectly true – that an MI5 anxious to ensure we continue to believe we live in a society which protects free speech would almost certainly staff newspapers with faux-conservative "assets" to lead people up blind alleys'.

I must ask him either to substantiate this allegation with facts, or to withdraw it and offer an unreserved apology. If he does neither then, under the usual rules, he will no longer be welcome here. I think a week should be enough. In case he has not so far seen this warning (first posted yesterday on the relevant thread) I will date that week from the publication of this posting.  I will listen to any reasonable request for more time but given his confident tone, I imagine he has the evidence at his fingertips and should rapidly be able to back up his claims. Or perhaps not.