[Supplier] What do you do when a stakeholder wants to single-source something before alternatives are properly evaluated?

I would not block the conversation emotionally, but I would slow it down enough to understand why they want that supplier. Sometimes there is a valid technical, timing, or relationship reason. Sometimes it is just habit or convenience. I want the basis for the preference made explicit before we lock ourselves into it.

If alternatives have not been properly evaluated, I would explain what risk that creates and what level...