Glenister - best known for playing DCI Gene Hunt in Life On Mars and Ashes To Ashes - came under fire for his use of an American accent on the show. He later defended the choice of accent, explaining that he 'wanted the challenge'.
A source told The Sun: "ITV spent millions on Demons - but things have not worked out. Philip made it clear he would not come back. He's busy filming with a second series of Ashes To Ashes and has other shows in the pipeline."
The Saturday night series, about a group of demon hunters, shed viewers in every week of its six-episode run, dropping to a low of 3.4 million for the series finale.
Discussing the future of the show, an ITV spokesperson said: "No decision has yet been taken."
> Cult Spy: Should Demons be smited?