Cabinet: CDS briefing and speaking notes for ?MOD Chiefs of Staff Committee - COS 57th Meeting/82 (0830Z) (Operation Corporate - intelligence, own forces, public relations, actions and decisions required) [declassified Spt 2017]

It is not absolutely certain that the speaking notes were intended for use at the COS. In the agenda they are noted as being "out to OD(SA)" - presumably in the briefing file for OD(SA) - and such notes make more sense in context of Lewin briefing politicians.

Yet there was no OD(SA) on 23 May and there is no recorded meeting between MT and Lewin or anyone else. She spent the day quietly at Chequers. Perhaps he went to Chequers and briefed her alone, the event going unrecorded.