One of his problems is that, over the last few weeks, many of the allegations made by republican sources have been wholly or partially borne out by events. The Government's line, by contrast, has been denounced as deceitful and dishonest by a stream of Unionist politicians, while on the nationalist side confidence in the Government has also noticeably dipped.
The first area of doubt will be in substantiating his assertion that the exchange of documents with the IRA took place in the context of an original IRA message declaring that 'the conflict was over'. The Secretary of State for Northern Ireland relies heavily on this point as a justification for opening up the subsequent dialogue by document.
But last night, the president of Sinn Fein, Gerry Adams, dismissed the claim that the IRA had initiated the contact by saying the conflict was over. He said that, in fact, the Government, not republicans, had made the first move.
Certainly there is little evidence in subsequent events to show that the IRA considered its campaign to be at an end. The initial contacts at the end of February were followed the following month by the Warrington bomb, and in April by the Bishopsgate explosion, while in Northern Ireland IRA activity continued at its familiar levels.
Sir Patrick's position is that the Government would only consider dialogue with republicans once violence had ended. Yet one analyst pointed out last night that the confidential advice note which Sir Patrick himself wrote to one of his representatives in the contacts appeared to assume that violence might well continue. The note stated: 'It must be recognised that all acts of violence hereafter could only enhance these difficulties and risks, quite conceivably to the point when the process would be destroyed.' Sir Patrick may be asked why he used such language to an organisation whose campaign was over.
It may also be argued that the fact that Sir Patrick passed on this and other detailed substantive points, via his representative, itself amounted to talking to the republicans, if at one remove. It is not yet clear whether he intends to publish these instructions today along with the documents.
If he does not, the suspicion will linger that important parts of the dialogue are being kept secret.