Berlin as a target in a British atomic-war counterfactual

Which city might Britain target if its independent atomic programme helped end the war against Germany?

Berlin is considered likely if Hitler remains there, with the delivery aircraft possibly concealed within a mass conventional raid.

In this scenario, Britain develops an atomic weapon while the war against Germany continues. Berlin is considered a likely target if Hitler is still there because the attack could remove the regime's leadership. The possibility is raised with an explicit personal reservation about choosing Berlin. Concealing the delivery aircraft within a mass conventional raid is another suggestion. Neither the target nor the method is presented as an established historical plan.