From about Jan 1965 it was decided that there would not be any TSR.2s in RAFG, and planned orders went from 158 to 110.
Ultimately the interdictor Canberras (and a squadron of recce ones IIRC) were replaced by Phantoms, and the order for F-4Ms was based on this plan. Of course F-4Ms and P.1127s also replaced the P.1154, so it is conceivable that the P.1154 could have replaced the interdictors (they had the range) in RAFG, but as things were all up in the air in the first few months of 1965 it was never put into any firm plan.
That said, the lecture this thread is for will be about discussing what did happen to the P.1154 (it was mentioned as a Lightning replacement in 1962, but not pursued far - Bill Gunston's Harrier book shows a GA for this, an RAF single-seat aircraft with a large radar). I'd be grateful for further Phantom/Lightning/P.1154 'what if' speculations to go into the thread we all discussed related things in previously (or a new thread):
http://www.secretprojects.co.uk/forum/index.php/topic,10445.0/highlight,1154+lightning+phantom.html
even if the Canberra is a squeeze there - I'd like to keep this thread for updates of the lecture.
Cheers
Mike