Political commitment in a Blue Streak survival counterfactual

How could Blue Streak have been made viable enough that it was never cancelled?

Make a fully independent nuclear deterrent an enduring national and political commitment shared by successive governments.

A completely independent nuclear deterrent would have to be an objective the government considered indispensable. That commitment would also need to extend to a potential successor government. The proposal ties the program both to an ideological view of Britain's future and to the governments' own political survival. The emphasis is on maintaining political backing across changes of government, rather than on a specific engineering revision to the missile.