I'm sorry my initial post was pretty lazy as distracted with work.
Yes I was referring to the P1154.
I was reading through this site as a point of reference
[URL="http://www.harrier.org.uk/history/history_p1154.htm"]http://www.harrier.org.uk/history/history_p1154.htm[
I guess asking if it was political or technological question isn't entirely asking it correctly.
With this project cancelled yet the continuation of the subsonic version I had wondered beyond the technological challenge of V/STOL how/why achieving a high Mach number was not pursued. Being simplistic about it, if you are going to have a jump jet why not have one that would also do Mach 2?