In his early 20s, the promising young actor Kenneth Morgan had already won the BFI’s Best British Newcomer Award. At that time, in the early 1940s, he must have felt as if the future held unlimited promise.

Aside from his acting skills, he had a mentor who was the most celebrated, debonair and well-connected playwright in the country. In Terence Rattigan, not only did Morgan have a champion, he had a lover.

It was a tempestuous affair and when Morgan broke away from his mentor, his career took a nose-dive. In 1949, in a seedy London bed-sit, he attached a rubber tube to his small gas ring and killed himself.

Terence Rattigan, capable of compartmentalising a life full of secrets, took his grief and turned it into his masterpiece The Deep Blue Sea .

“The Deep Blue Sea a story about a woman who kills herself. At the time, you couldn’t discuss homosexuality so he wrote a male and female story,” says two-time Olivier nominee Paul Keating, who plays Morgan in Mike Poulton’s new play Kenny Morgan at Arcola Theatre.

Paul, who lives in Mile End, said: “There’s very little on paper about Kenny because he died very young but he was in a quite desperation by the time we pick up on his life.”

In Poulton’s play, Morgan’s suicide attempt fails and his neighbours call the first name in his address book – Terrence Rattigan.

Paul said: “Any actor will recognise those moments when you are really down on your luck. I’ve had plenty of barren times. You have moments when you look at yourself and think ‘should I be doing this any more’. It can be quite desperate.

"I’ve never got to the stage where I’m thinking of topping myself, thank God, but I think I can understand that level of desperation. You have to find things to keep yourself occupied.

"During my early career I was spoilt because I was able to earn a living just from acting but in the last 10 years it’s been I’ve had to find other things.”

Paul is better known for his work in musical theatre but is looking to broaden his experiences.

“I’ve been trying to do more plays and get more experience in this sort of world. It is difficult, especially in London to get out of the box and not be seen as a musical theatre performer. I’m really fortunate that I worked with Mike Poulton on a play about 11 years ago that did really well and he’s been really loyal since then.

“I love musicals but I feel I’ve done my fair share and I’d like to do other work. This part goes through the gamut of emotions so it’s going to be challenging – and slightly terrifying – but when I read it I thought this is a godsend, it’s a real gem of a part in a really brilliant play.”

And this is his first time at the Arcola theatre, just down the road from where he lives. He said: “It’s a wonderful space and it’s really nice social place – it’s got a bar and a coffee shop and two theatre spaces and rehearsal space – it’s all here. I can get the 277 and I’m here in 15 minutes – I’m laughing all the way.”

Arcola, May 18-June 18, £12,