Literal of enum values

I am trying to implement a function that, as the type of one argument, can accept either an Enum or a value of such an enum (because some Python programmers are more used to type strings instead of enum values). Currently I have managed to do the following:

class LinkageCriterion(enum.Enum):
    WARD = "ward"
    COMPLETE = "complete"
    AVERAGE = "average"
    SINGLE = "single"


LinkageCriterionLike = Union[
    LinkageCriterion,
    Literal["ward", "complete", "average", "single"]
]

My question is if there is a way to not repeat myself here, that is, if you can construct a Literal from the values of a given Enum, and if so, how?

Start by checking the Python typing specification and the behavior of Literal with Enum values. Compare the requested LinkageCriterionLike pattern with current typing support, then document whether enum values can be derived automatically or what limitation remains.