The series is loosely inspired by the film Staircase (1969) which starred Rex Harrison and Richard Burton as a pair of aging queens, exactly like Freddie and Stuart in this series.
Freddie Thornill (Ian McKellen) mentions several times that he was in Doctor Who (2005) and was voted 10th Popular Villain; McKellen did actually voice the Great Intelligence, a popular villain, in the Doctor Who (2005) 2012 Christmas Special "The Snowmen". Derek Jacobi (Stuart Bixby) has also appeared as Professor Yana/The Master in the Doctor Who (2005) episode "Utopia".