“Well, I’m extremely vain and very easily flattered, so the first reason I was attracted to the role was because I was told it was written for me, and there’s nothing more delicious than that,” comes Celia Imrie’s, for want of another word – delicious – voice down the receiver, softly caressing the phone line. We’re talking about her latest part in upcoming romantic comedy Finding Your Feet and although I can’t see her, I can picture her, with an almost imperceptible, wry smile forming at the corners of her mouth.

Imrie is no stranger to turning on the charm. In the past two decades we’ve seen her play Una, the meddling, gravy-sieving, tarts-and-vicars-party host in Bridget Jones’s Diary; require ‘considerably bigger buns’ to protect her modesty in Calendar Girls; and hotfoot it to India in search of a husband as incurable flirt Madge Hardcastle in The Best Exotic Marigold Hotel.

In Finding Your Feet she stars alongside fellow household names Imelda Staunton, Timothy Spall and Joanna Lumley as the bohemian, free-spirited Bif. “I found her irresistible,” she says, savouring every word until it resonates crisply and coquettishly. “My rather fabulous manager in LA said a part must be that – ‘irresistible’ – and so that was Bif.”

The film, which is released in February, has feel-good written all over it. In it, straight-laced housewife Sandra (Staunton) discovers that her husband of 40 years has been having an affair with her best friend. She flees to London to stay with her estranged sister, Bif (Imrie), who persuades her to step out of her comfort zone and begin again – starting with dance classes. It’s that sort of second-chance-at-life flick that even the staunchest cynic can’t help but feel a bit warm and fuzzy about. And it’s the sort of role – full of fun and mischief – that I imagine must suit Imrie down to the ground.

“It’s better than a misery moment isn’t it?” she says. “Having said that, although it’s great to make people feel good, because why not – I now want to scare people out of their pants.” She’ll be attempting to accomplish that later this year with her first horror film Malevolent. “That won’t make you feel good,” she quips.

But has comedy always come naturally?

“Well, I’m not sure I’m allowed to answer that,” she demurs. “I’m intoxicated by the sound of people laughing at me. I have been since I was a child. Of course you don’t necessarily know if that’s going to happen in a film until you see it with an audience, so that will be quite thrilling.”

“I’m intoxicated by the sound of people laughing at me. I have been since I was a child”

Although eternally daunted by the prospect of watching herself on-screen, largely because she admits it’s hard not to be critical of your own part, Imrie enjoys seeing how a film comes together. She’ll also have Staunton, Spall, Lumley et al for moral support at the premier. “We’ve all worked together before, so there’s a sort of shortcut through to getting on with it because you know each other,” she says.

One scene she is particularly looking forward to watching back is a dance routine performed to an unsuspecting crowd in the middle of Piccadilly Circus, in the pouring rain – “it was absolutely heart-stopping” – although she laments that her character wasn’t in the front row.

She loves to dance off-camera, too. “I still think I can pirouette like I used to years ago, but I generally overbalance nowadays. Any kind of waltz will always get me going,” she adds, conspiratorially like she’s sharing a dirty secret. “Or a Scottish reel – I’ve had many a happy moment dancing around kitchen tables to a Scottish reel.”

At 65, Imrie shows no sign of slowing down. The idea of taking time off horrifies her. “I have absolutely no intention of retiring because actors don’t really, so that word is alien to me,” she insists.

When she’s not travelling for filming commitments, she escapes to her second home, on the coast in Nice. I say escape, but she’s actually busy penning another novel, her fourth, when we speak (her debut Not Quite Nice reached number three in The Times Bestseller List). She tells me she first picked up a pen in a bid to gain more control. “I wrote in my autobiography that as an actor ‘you have to wait to be asked to dance,’ and that can be frustrating. So I thought I’d write a story.”

She wants all her books to be adapted for film, in particular her latest, the soon to be released Sail Away. It tells the story of two women who find themselves on an eventful Atlantic crossing – one is an actress in her 60s who is struggling to find work. Imrie has had no shortage of roles of late, but is ageism rife in the industry?

“I think getting older makes you a little more daring,” she begins, adding quickly: “but I’m jolly lucky to be the age that I am and find that the tide has turned towards this sort of age group. It won’t last but I’m going to make the most of it while I can.”

Sail Away, she says, was first and foremost inspired by her soft spot for cruise ships. She loves the glamour of the American voyage on the Queen Mary 2 – it’s her preferred mode of transport when she heads Stateside. She’s spent much time over there lately filming the FX series Better Things, a semi-autobiographical comedy from Pamela Adlon in which Imrie stars as Phyllis, the eccentric parent of Sam Fox (Adlon), herself a single mother working in Hollywood. The razzmatazz of Tinseltown has never been enough to lure Imrie there permanently, however.

“The most important thing to be doing when you’re in Los Angeles is working because work is the whole engine of the place. If you are, it’s heaven, but if you’re not I think it would be rather a lonely place,” she says.

She’d prefer to be at home in Notting Hill with her son Angus, also an actor. Downtime chez Imrie might consist of watching Family Guy and Creature Comforts, before heading for a walk in Holland Park (“I never tire of it”), or around the lake at Kensington Gardens. Imrie’s other favourite local pursuits include breakfasting upstairs at Le Pain Quotidien and dinner at De Amicis or Portobello Pizzeria.

Not that there will be much time for dining out over the next couple of months, what with the release of Finding Your Feet and Sail Away just one day apart. And that’s just for starters. Next up, you can see Imrie in Channel 4’s Hang Ups with Stephan Mangan, a comedy about an unconventional therapist that was entirely ad-libbed (“there was something terribly attractive about the idea of not having to learn lines”) and starring in Patrick Melrose, a Showtime series, alongside Benedict Cumberbatch. Listen out for her in animated comedy Monster Family too, with Emily Watson, Jason Isaacs and Catherine Tate.

“I love not knowing what’s going to happen next. The only thing I do know is that I’m jolly well going to make the most of every second,” she says. Her only regret is that she wasn’t a bit pushier sooner: “I’m having a go now,” she purrs, wickedly. “You need a bit of cheek to do that…”