The 56 engined lifting platform was a project of Short Brothers. NATO had issued a request for proposals for a Mach 2 strike aircraft to replace the Canberra, with a declared preference for V/STOL.
English Electric proposed the P17/a aircraft, and in partnership Shorts proposed the P17/d lifting platform. The French proposed a Mirage design with separate lift engines. (I believe the only supersonic VTOL aircraft to actually fly until the JSF contenders).
When the difficulties of producing an aircraft to meet the required capabilities came to light the V/STOL requirement was dropped. The government favoured a joint venture between English Electric and Vickers Armstrong and the TSR2 was the result.
Blackburn aircraft proposed the B.150, essentially a Buccaneer with reheated Speys, longer thinner fuselage and thinner wings. It fulfilled the majority of the requirements and would have cost much less than TSR2, but the RAF wouldn't have anything to do with a Navy plane, and the project went no further. (Lord Mountbatten later went on to persuade the Australians not to buy TSR2 in favour of the Buccaneer, although they then went on to buy the F111 instead)
pilot-lite