UK IC suppliers:
- Hitachi (80x family)
- CAF (397 / Mk5 coaches)
- Stadler (GA FLIRT, and they also bid a FLIRT/SMILE for the EMR IC contract)
- I believe Talgo has also bid for UK IC contracts
so while Hitachi is very big in the IC market, they are definitely not the only game in town
Talgo bid for the HS2 rolling stock contract, and so did Siemens.
All except Stadler can offer UK assembly of their trains (Talgo would have built their HS2 trains in Scotland).
With the HS2 contract sewn up (Hitachi/Alstom), and all the recent Hitachi 80x deliveries, there is little to compete for in the IC market in the next decade.
The procurement priority is for bi-mode/battery/hydrogen regional trains.
Alstom has solutions but they are not for UK gauge, or designed in Derby.
An Alstom-Stadler joint bid might work, though, if it was for a decent order volume.