In court cases, ideally you save the crystallization of your argument for summing up, because if you reveal it too early on you give the opposing side the opportunity to rebut it.
I like to hope that's Starmer's strategy. If he says anything too exciting too far for an election, it gives the Tories an angle, and time to spin nonsense against him. But you can't punch fog.
Government makes last minute change to National Curriculum with addition of classes in ‘Holding up bits of Classroom’
https://newsthump.com/2023/09/05/government-makes-last-minute-change-to-national-curriculum-with-addition-of-classes-in-holding-up-bits-of-classroom