hot potato

A sensitive situation or controversial issue that is difficult to handle and thus gets passed from one person to the next (like a potato that is too hot to hold). The political candidate knew the issue was a hot potato, so he deferred to his chief of staff, who directed questions to the committee chairperson.

A problem so controversial and sensitive that it is risky to deal with. For example, Gun control is a political hot potato. This term, dating from the mid-1800s, alludes to the only slightly older expression drop like a hot potato, meaning "to abandon something or someone quickly" (lest one be burned). The idiom alludes to the fact that cooked potatoes retain considerable heat because they contain a lot of water.