A later bit talks about the show being "quietly queer" and give a quote, attributed to "Robert" (but I think they mean Natasha Hogman given the context and flow) -

"Just because it's a story about a load of old white men doesn't mean it has to be told that way."

So, in #OperationMincemeat, all the cast play multiple parts of multiple genders, but I want to point out that:
* Jak Malone is nominated for Best Supporting Actor in a Musical - his main role is Hester Leggat (female)
* Zoe Roberts is nominated for Best Supporting Actress in a Musical - her main role is Jonny Bevan (male)
* Natasha Hodgson is nominated for Best Actress in a Musical - her main role is Ewan Montague (male)