It’s A Sin star Keeley Hawes said she cannot stop herself crying when discussing the drama, such is the bond between her and her co-stars.

The acclaimed actress plays the mother of Olly Alexander’s lead character Ritchie in the Channel 4 series, which is set in London during the HIV/Aids crisis of the 1980s.

It’s A Sin is created by Russell T Davies, also the writer behind ground-breaking 1990s series Queer As Folk.

Keeley Hawes
Keeley Hawes stars in It’s A Sin as the mother of a gay man (Ian West/PA)

Speaking during an event for the BFI At Home series, Hawes fought back tears and said: “I’ve been doing interviews and I can’t talk about the cast and how gorgeous and generous they were to me.

“I can’t talk about the characters. You carry them with you, they don’t leave you. And that is down to the cast and down to their performances and down to Russell’s writing.”

Hawes, known for her work on Line Of Duty and Bodyguard, revealed that as soon as she heard about It’s A Sin she turned to actor husband Matthew Macfadyen and told him she wanted to appear in it.

She said: “I read the press release about the show and I said to my husband, ‘oh my God, I’d love to be in that’.”

Hawes, 44, plays Valerie in It’s A Sin, the mother of Ritchie, a young gay man. She is described as “a product of her generation”. The actress discussed the challenge of making a dislikeable character empathetic for viewers.

She said: “Valerie is someone who is very easy to dislike and so the trick was bringing something likeable to her because we have to have empathy with her.

“And I do. I knew women like that, I knew people like that. At her core she adores her children and her son. In her heart she adores him.”

It’s A Sin starts on Channel 4 on January 22.