‘You wiped the floor with me!’ Tamsin Greig and Oliver Chris are having a riot with Rattigan

On 8 May 1956, Terence Rattigan stood outside the Royal Court theatre in London after the opening night of a revolutionary new drama. This was not one of his own plays but a sally from the upstart generation: John Osborne’s Look Back in Anger. Or, as the veteran playwright bitterly renamed it: Look How Unlike Terence Rattigan I’m Being. Refinement was out, the Angry Young Man was in, and the author of Separate Tables and The Winslow Boy had plummeted from favour.

But that all changed in 1993 – with Karel Reisz’s revival of The Deep Blue Sea, Rattigan’s most penetrating work. Penelope Wilton played Hester Collyer, who is separated from her husband, a primly patriarchal high court judge. She now lives in sin with her younger lover, the carousing ex-RAF pilot Freddie Page. The play begins with Hester’s listless body being discovered by her neighbours. She has tried to gas herself after Freddie failed to return for her birthday. (She would have succeeded had there been enough coins in the meter.) The rest of the day, and the play, is spent raking over the detritus of her life. Freddie bowls in obliviously; her husband tries to coax her back to the marital home; and the enigmatic former doctor, Miller, exhorts her to “go on living”.

Tamsin Greig, who at 57 is about to play Hester in a new production, saw Reisz’s version when she was starting out as an actor. “I was blown away,” says Greig, eating a salad roll in a church hall during a break from rehearsals. Seated beside her is Oliver Chris, her 45-year-old co-star from the surreal hospital sitcom Green Wing, who is playing Freddie. “It was so captivating,” Greig marvels. “Penelope gave such a deep performance.”

Previous generations had puzzled over Hester, who combines formidable intelligence with delusional yearning, regarding others with clarity from within her own fog of shame. (Each night before stepping on stage during a 2016 revival, the late Helen McCrory listened to Amy Winehouse’s You Know I’m No Good.) The character was inspired by Rattigan’s ex-lover, the actor Kenneth Morgan, who had left the playwright for another man, only to then gas himself when that new relationship hit the rocks. Rattigan, distraught to learn of Morgan’s death, was already converting it into drama that same evening. He was heard saying to himself: “The play will open with the body discovered dead in front of the gas fire.”

The Deep Blue Sea premiered three years later, in March 1952. The original Hester, Peggy Ashcroft, fretted that she couldn’t possibly make her character sympathetic. The Observer critic Ivor Brown wrote that Hester “needs a good slap or a straight talk with a Marriage Guidance Expert”. Times change. Contemporary critics admired the traces of Racine, and of Greek tragedy, in Wilton’s performance. The Guardian’s Michael Billington said Ashcroft showed Hester to be “painfully aware of the humiliating cost of her fixation” with Freddie, and called the role “one of 20th-century theatre’s best parts for a woman”.

Greig, who has short, choppy silver hair and is wearing a powder-blue jumper, weighs the challenges of an approach in the 21st century. “Peggy Ashcroft said she felt as if she had no clothes on when she was playing the part. I think we’re in a slightly different place now. If we don’t have our clothes off, literally or psychologically, then people feel a bit cheated. It’s about how to be uncovered while still hiding something.”

She and Chris, who is busy trying not to spill his chicken wrap down his navy-blue sweater, are best known for comedy. Greig has starred in some of the funniest sitcoms of the last 25 years – not only Green Wing but Black Books, Episodes and Friday Night Dinner – while Chris’s credits include the West End and Broadway runs of One Man, Two Guvnors. They last appeared together on stage in a 2017 gender-fluid Twelfth Night: Greig was Malvolia in a witchy black wig, Chris a boisterous, boxing Orsino.

Although you wouldn’t necessarily know it from Terence Davies’s austere 2011 film of The Deep Blue Sea, which starred Rachel Weisz and Tom Hiddleston, there are mordant laughs in Rattigan’s text, which crackles with gallows, or gas-leak, humour. “It is funny,” Greig agrees. “The humour is a coping mechanism. It makes you ask: what’s beneath the tip of that iceberg?”

She mentions an amusing exchange in the play about Lyme Regis, which causes Chris to let out a sulky harrumph. “I don’t think I’m going to get any laughs in this,” he says. “And if anyone else does, I’m taking them down.”

“If anyone looks like they’re getting a laugh, I’ll tell them, ‘Stop!’” Greig assures him.

“That’s it,” says Chris. “‘Stop! You don’t know what he’s like!’”

Greig warms to the idea: “He’s tall but he’s fragile.” Then she thinks for a moment. “Fragile because tall?”

“You’ve hit the nail on the head,” says Chris.

Their banter is near constant: he teases Greig for nibbling her lunch “like an Edwardian countess”, while she draws attention to his Trevor Howard-style period haircut. When they met 20 years ago on Green Wing, things were very different. Although Chris had appeared in The Office, he felt “very intimidated by all these comedy people”. He turns to Greig: “During our improvisations, you wiped the floor with me! I was throwing you duff ball after duff ball.”

“The weird thing for me now,” she says, “is having to be passionate – when Ollie and I have mucked about in our other jobs. I’ve got to the age where you think, ‘Oh, that sort of acting won’t be required any more. I’ll just need to be frightening or controlling.’ But playing Hester is about being vulnerable, as well as being an object of desire. It’s about showing underbelly.”

All this tomfoolery leaves one quite unprepared for their rigorous approach to Rattigan’s text. Asked to explain its enduring power, their focus sharpens instantly. “These are modern ideas he is addressing,” says Greig. “This thing of being kind to yourself, ‘living your best life’ as we say now. Hester asks whether criminals can escape their sentence and Miller says, ‘Yes, if the judge is fair – and not blind with hatred for the criminal – as you are for yourself.’ That’s a very modern take on self-care.”

“Do you think Hester is both the protagonist and the antagonist?” asks Chris.

“Haha! Yes!” Greig exclaims. “It’s like that psychotherapeutic view of dreams, which says every character is you.”

“She’s got to win the battle,” Chris says. “Maybe that’s why Peggy Ashcroft had those issues about being unsympathetic. What she might have discovered is that Hester is in a battle with herself.”

Greig asks Chris where that leaves his character, Freddie. “It’s complicated,” he says, brow creasing. “You’re presented, on the surface, with someone who is irresponsible and childish, out of their depth, unable to function in society and in this relationship. But even as Freddie gets progressively drunker, there are points where he makes quite a good argument. He’s trapped, too. He’s struggling.”

Freddie’s reaction to accidentally discovering his lover’s suicide note is to storm out and get sloshed. “Suicide is part of the play,” Chris concedes. “But think about the impact that has in the real world. This guy has come home and discovered that the woman he loves has tried to kill herself, arguably because he forgot her birthday. That’s going to send even a reasonable person spiralling.

“Look, I don’t have a huge connection with suicide, but when I was a kid, my best friend from infant and junior school – we’d since grown apart – killed himself at 16. The thing I remember from the funeral is his parents’ anger. His dad gave the eulogy and he was livid. So there is that impact. The idea that Freddie has been on the end of a near-miss and is going to kick up all the silt and ashes and embers of everything. Then he grabs on to whatever there is – and it’s a bottle.”

At one stage, Freddie slams a shilling down on the table so that Hester’s next suicide attempt won’t fail. Greig argues that even this apparently callous act is more complex than it seems. “I think it’s about choice,” she says. “He leaves the coin. Miller gives her the sleeping tablets. There’s a bottle of whisky, a bottle of claret. They’re challenging one another. ‘These are the things you have been using – and I challenge you to see that.’ Miller says it at the end: it’s Hester who has the power to choose.”

Chris seems grateful for Greig’s advocacy on behalf of his character. “I do feel defensive of poor old Freddie,” he says. “He literally spells it all out: if a person loves you in a certain way, and you can’t return the affection, what are you meant to do?”

“That’s the human condition,” says Greig. “We all love differently. The question is, ‘How do we live with that?’”

• The Deep Blue Sea is at the Ustinov Studio, Theatre Royal, Bath, until 1 June.

• In the UK and Ireland, Samaritans can be contacted on freephone 116 123, or email jo@samaritans.org or jo@samaritans.ie. In the US, you can call or text the National Suicide Prevention Lifeline on 988, chat on 988lifeline.org, or text HOME to 741741 to connect with a crisis counsellor. In Australia, the crisis support service Lifeline is 13 11 14. Other international helplines can be found at befrienders.org