The first programme cut is uncertain, but the F-35A purchase is questioned

What part of the plan is most likely to be cut first by an incoming government facing a financial crisis?

There is no confident prediction. Buying F-35Bs instead of a token fleet of twelve F-35As is preferred, but that change would leave the wider funding shortfall unresolved.

Which programme an incoming government would cut first is left uncertain. The preference expressed is to buy F-35Bs instead if the alternative is a fleet of only twelve F-35As. The extra expense of the A variant is judged difficult to justify at that small scale. Cutting such a programme would still leave an already underfunded defence plan, so the potential saving is not treated as a solution to the wider problem.