"I have some faith in the Great British underdog, small teams, well managed with sound governance "
yes but aerospace requires billlions to bring a new aircraft to completion. IIRC 30 years ago it cost Gulfstream US$ 800 million just to upgrade the GIV to the GV - and that was a well established company with years of experience. These days it would cost well over a Billion. And that's not a new aircraft.
It's not just the prototypes - the cost of certification is enormous. You're looking at hundreds if not thousands of hours of flying ..........