One of Britain’s most iconic actors is joining the cast of EastEnders has part of a hard-hitting new storyline.

Just weeks after the soap celebrated its 40th Anniversary, Trainspotting star Keith Allen is set to appear in a ‘mᴀssive’ new signing.

The star will play Gaz, a mysterious new character as part of a special episode focused on Phil Mitchell and his struggles with his mental health. 

EastEnders has worked closely with charities The Samaritans, Rethink Mental Illness, the Campaign Against Living Miserably (CALM), and Mind to ensure Phil’s story is portrayed as sensitively as possible.

Set across four weeks, the episode will focus on Phil’s journey in the mental health unit from the moment he starts treatment.

The episode sees Phil prepare to face his inner trauma and understand what may have contributed to his depression diagnosis and his symptoms of psychosis.

Iconic British actor Keith Allen has joined the cast of EastEnders in a hard-hitting new storyline with viewers set to get a glimpse into Phil Mitchell’s mental health woes in a special episode

Keith is best known for a string of film and TV roles, including Trainspotting, The Others and more recently, The Buckingham Murders.

But he’s also the father of two very famous offspring, with singer Lily Allen as a daughter, and Game Of Thrones star Alfie Allen as his son. 

Speaking about his role, Keith said: ‘I’ve written a number one hit single, I’ve presented Top of the Pops, I’ve played the lead in the West End and I was at Craven Cottage when we beat Juventus 4-1…Could it get better than that?

‘Well, yes, I’ve just guested in an episode of EastEnders…What a joy! And what an honour to be a part of Steve McFadden’s incredibly moving story line.

‘I may be a resting actor but I now rest in peace.’

EastEnders boss Chris Clenshaw added: ‘I’m delighted to welcome the incredibly talented Keith Allen to the cast of EastEnders as he takes on the guest role of Gaz in a special episode focusing on Phil’s mental health. 

‘As Phil struggles to begin treatment, we explore how his relationship with fellow patient Gaz, helps Phil to take the first step in his road to recovery.

‘Keith and Steve’s performances are both phenomenal, and thoughtfully and sensitively portray the complex realities of mental health recovery and the impact of hypermasculinity.’

Set across four weeks, the episode will focus on Phil’s journey in the mental health unit from the moment he starts treatment

As well as his own acting plaudits on film and TV, Keith’s daughter is singer Lily Allen (pictured in 2007)

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During EastEnders’ 40th Anniversary episodes last month, viewers praised actor Steve McFadden’s performance as Phil finally decided to seek help for his mental health struggles. 

At one point, Phil locked himself inside the Arches and attempted to poison himself, leaving fans concerned for his fate. 

The scenes also saw Phil’s brother Grant Mitchell (played by Ross Kemp) make a surprise return to the Square, though he struggled to understand his brother’s deteriorating mental state.

It took Phil’s friends Nigel Bates and Linda Carter to convince him to be admitted to a mental health unit for treatment.

EastEnders airs on Mondays to Thursdays at 7.30pm on BBC One. The show also streams on BBC iPlayer, where episodes drop early at 6am.