Phil has been locked up in jail over the past few weeks, and the upcoming special will provide an exclusive insight into what life has been like for him behind bars.
The Red Button audience will follow Phil as he is given the task of showing a young new prisoner named Devon (Tobi Bakare) the ropes.
However, trouble lies ahead for the pair when Devon starts to clash with the prison's dangerous top dog Craig Jenkins (Glenn Doherty), leaving Phil with a decision to make about whether to protect him.
An EastEnders statement teased: "How far is Phil prepared to go to save someone else? The red button is sure to reveal all."
Phil was sent to prison earlier this year after his own son Ben (Joshua Pascoe) falsely told the police that he was responsible for the death of Stella Crawford.
EastEnders fans can see Phil's BBC Red Button programme on Monday, March 12 from 8.30pm, straight after the regular episode of the soap.
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Watch Phil Mitchell's EastEnders character trail in the video below: