How could Britain get the Lion-class battleships into service?
Short answerKeep construction moving by building enough sloops before the war that emergency escort needs do not displace the capital-ship program.
NotesThe direct answer is to keep building the Lion class rather than suspend the program. Historically, the urgent need for escorts helped force pauses in capital-ship and carrier construction. A larger prewar inventory of roughly 360 sloops would reduce dependence on emergency corvette construction. The counterfactual depends on earlier investment in unglamorous escort capacity, rather than simply protecting battleship funding after war begins.