Asking for clearer priorities when every task is labeled urgent

Every item in my queue has acquired an ‘urgent’ label. When I ask what can wait, I'm told they're all important, which doesn't help when several deadlines overlap. I want to make the tradeoff visible without sounding unwilling to work. I'm considering a short list of tasks with estimated hours and asking my manager to choose which deadline moves. How do you phrase that conversation so it becomes a priority decision instead of a complaint?