The one "high tech" project to escape in the 1960s was Concorde, and this was attributed entirely to MP Tony Benn having a marginal Labour seat at the Concorde factory in Bristol (he'd already lost the seat once and regained it).
I thought Concorde survived because of the 'no get-out' clause negotiated with the French by Conservative minister Julian Amory. It was, ironically, devised so that the French couldn't pull out and leave the Brits with all the costs.
Ironically, it turned out to be us that wanted out, but were tied in by that clause!
SSD