Rachael Stirling: ‘Promise me you’ll take out half the swearing?’

Since scandalising BBC viewers more than 20 years ago in Tipping the Velvet, Rachael Stirling has become one of our most sought-after actors on stage and screen. Other TV credits include The Bletchley Circle, Women in Love and Mackenzie Crook’s Detectorists. She’s now in rehearsals for the Donmar Warehouse’s new production of Noël Coward’s comedy Private Lives, in which she and Stephen Mangan will play Amanda Prynne and Elyot Chase, a divorced couple who can’t resist one last hurrah. The 45-year-old Stirling – whose mother was the late Diana Rigg – is married to Elbow frontman Guy Garvey, with whom she has a six-year-old son.

How are preparations for Private Lives?
They are full of joy. It is one of the most pleasurable parts to play and story to tell – this very passionate, narcissistic, combustive, dangerous, costly and hilarious relationship. And to be able to do it in the Donmar, where no audience member is more than four rows away… They are in your armpit, they can smell the sweat and see up your nostrils, so you’ve got to be on your game or you will be exposed.

The Observer’s 1930 review of the original production noted that the play “could not stand up to the slightest clumsiness in the acting”. Do you agree?
Yes, I do. You have to have two actors who trust each other totally, and who aren’t playing stupid fucking ego games outside of the stupid fucking ego games that their characters are playing. Otherwise, you’d have just too many explosions going on.

So it’s a nightmare being paired with Stephen Mangan?
[Laughs] Steve Mangan is just the dream. There are many actors whose balls you have to cup in order to be able to… [More laughter] If you have a funnier line, you have to sort of soften the blow. But not this man; this man can stand up to anything.

How does your version differ from other revivals?
We’re doing the grittiest version of it. We’ve got some proper scrapping, battling going on: I’ve got a torn pectoral muscle that’s just about hanging on. So we need to get fit. All that fighting and fucking every night is going to be exhausting!

Sold! Recently, you’ve appeared more in theatre than on TV. Is that your preference these days?
I get offered the great, big, thwacking, gorgeous parts in the theatre. And telly not so much. I come back to do things like Detectorists because it’s the gentlest, wrapped-in-the-arms-of-Mackenzie Crook, nothing-can-go-wrong experience, but I’m just a bit pickier about telly.

Will there be more Detectorists?
No, definitely not. We auctioned off the Triumph TR7 for Red Nose Day. That’s all, folks.

Is it true you proposed to Guy Garvey on a leap year?
I did. I asked my beloved to marry me. I went with my brother to Halfpenny Bridge off Harrow Road [in west London], where I lived, and we bought loads of chalk and I wrote on the bridge: “Marry me, Shindig,” which was my name for him. And then squirted it with hairspray, in case it rained.

Why “Shindig”?
It’s because when I met him, the first thing I said to him was: “Ahhhh, you use the word ‘shindig’ in one of your songs.” Because I really enjoy that word. And Guy came back with: “I’ve also used the word ‘shenanigans’.” And that’s when love was born, is all I can say.

Has living with him changed the way that you work?
I used to be a nervous improviser, but now Guy and my son will just improvise songs or gags and I’ll join in. He’s made me less afraid of constantly coming up with daft shit. [Less afraid of] that little critic on your shoulder saying: “That’s not good enough.” It’s been a revelation that everything is on the way to something.

There was a period about 10 years ago when you stopped acting for a few months. Did you always know you’d come back to it?
No, I’d broken up with somebody and, in order not to get depressed and fall down, I needed to go and do some manual labour. I mean, let’s face it, I didn’t go down a coalmine, but I went to go and work in a pub for a bit. And do some people-watching and clean up some sick. It was very grounding.

Did the break make you appreciate acting?
When I was much younger, I was sent off for auditions for a Bond movie [Casino Royale]. And I just remember, I thought: “This is not me. I don’t feel like a Bond girl. This is awful.” I found myself being told what it was I ought to want and it was never what I wanted. I’ve always been a pathetic people-pleaser, but perhaps birth and death and all these things have made me less so.

Do you have any cultural recommendations?
I’m going to the brilliant Lisa O’Neill gig at the Barbican. On TV, Guy and I are just lapping up the new Ted Lasso. That’s not the most imaginative answer, but it’s kind – it’s not cruel telly. And introducing my son to [David] Attenborough has been one of the greatest joys. Attenborough’s documentary about the titanosaur – his eyes nearly popped out of his head. So now that’s become our Sunday night thing.

What’s your happy place?
I do ballet with a gorgeous ex-ballerina called Charlotte Toner. I played Marie Rambert in a drama about 15 years ago and I had to go and train with the Birmingham Royal Ballet and I remembered how much I loved it. She’s totally changed my brain and body, and I do it with women from all walks of life. Some can get their legs up to their ears and some, like me, can’t quite.

Thanks Rachael, it’s been great speaking to you.
Promise me, Tim, that you’ll take out half the swearing? Only leave in the very funny “fucks”.

• Private Lives is at the Donmar Warehouse, London WC2, from 7 April to 27 May