Ashley Jensen has seen her career shift from sidekick to leading lady and it is one she has earned, she reckons.

The Annan actress is used to hard work and explains: "I think because I started at the bottom, I was the day player who came in for the day, so I've done all that.

"I feel as if I've very much served an apprenticeship," she confides, having made her name as the hapless Maggie Jacobs in Ricky Gervais' Extras over a decade ago.

"I know how to conduct myself and I very much feel that [a job] should be a collaborative thing. I just happen to be the person who is, I suppose, in all day every day. And that's fine; I feel ready for it," she adds, before turning to whisper "I think".

Jensen is being modest, of course. For only last year she shone as the front runner in Agatha Raisin, the Sky One comedy based on the much-loved books by M.C Beaton, about a glossy London publicist who turns amateur Cotswold detective.

"Desperate Housewives crossed with Midsomer Murders" is how she described it at the time - a welcome change for the actress who, herself, admits she's made "an entire career playing people's best friends" in such TV hits as Catastrophe and Ugly Betty.

But fast forward nearly 18 months and Jensen, 48, is set to flex her dramatic muscles as the star of the show in brand new BBC drama Love, Lies & Records.

Penned by Kay Mellor (the BAFTA award-winning writer behind such hits as Fat Friends and In the Club), the BBC One series follows Kate Dickenson (Jensen), a town hall registrar who, like many of us, is torn between her home and work life. In her case, a partner and demanding teenagers versus the daily dramas of births, marriages and deaths.

"It's the working mum thing, isn't it?" asks Jensen, who shares an eight-year-old son with her husband - and fellow actor - Terence Beesley. "It's the whole, 'I'm doing a job and I want to do it to the best of my ability, but I'm also someone's mum and I'm also someone's wife', which a lot of women do. It's a reflection on society.

"It's interesting, somebody asked me the other day about reality television - I have to admit I don't [watch it], but they said: 'Don't you think it is a reflection of the society that we live in?' And I said: 'No, I don't really, because I think quite a lot of it seems, to me, contrived and a little bit forced.'

"But that's what I think good British drama does," she insists. "When it's written as brilliantly as the stuff that Kay writes, It's holding up a mirror to society and hopefully people can tap into that and understand it."

In the same vein, Jensen praises Mellor for scratching beneath the surface when it comes to people and their passions, stating "there's no baddies and no goodies, it's just about truth".

"It's very pertinent to the world we live in, with people from different cultures, transgender, families on second marriages and families with stepchildren," she says of the themes that resonate between the much-loved cast, which includes the likes of Adrian Bower, Kenny Doughty, Rebecca Front and Mark Stanley.

"In some ways it's all quite messy, everything's quite messy, but people's lives are all a little bit messy," she notes. "I think that everybody aspires to perfection but if we all actually dig a bit deeper, everybody is floundering a little bit.

"But looking at people's Instagram pages, everyone is living a perfect life," she adds, smiling. "I don't do Instagram, Twitter, Facebook ... I'm a Luddite, I take myself away from it. But from what I perceive that's what it is."

Jensen, who grew up in Annan, always longed to act, first spending a few weeks in London with the National Youth aged just 14; and later studying drama at Queen Margaret University.

The former Annan Academy pupil always wanted to become an actor.

She said: "In the days of tape decks, I used to do little radio shows, and I did impressions of the wonderful Terry Wogan. I'd have little guests that would come on, and I'd do Miss Piggy and Frank Spencer - Michael Crawford is my ultimate hero.

"He was the reason I wanted to act; I thought his performance as Frank Spencer was just genius. I love comedy when it can be physical as well as written - for me, nobody did that better than Michael Crawford."

That humble start with her tape decks has taken her from Annan to Hollywood but she remains down-to-earth and a popular figure in her hometown where she is warmly greeted by friends and admirers whenever she's spotted making a visit to mum Margaret, who still lives there.

And she's certainly not shy about where she's come from, having famously spoken of her love of fish and chips from Annan's renowned Cafe Royal on national television.

From landing her first big TV break in the 1993 drama Down Among The Big Boys to spending a six-year stretch in LA for Ugly Betty, and stripping off in front of Colin Farrell for dystopian film, The Lobster, Jensen is indeed committed to her craft.

When learning her "fair few" lines for Love Lies & Records, for instance, she confesses to "living like a nun".

"I would literally go home, have my little bowl of soup, read my lines, and then put my lines under the pillow thinking they would go in by osmosis," she says, with a laugh.

Praising the registrars she met in preparation for the part, she follows up: "I suppose, like Kate, I would get very much involved with everybody's story [if I did her job].

"To be honest, I'm kind of exhausted. At the end of the week I'd feel absolutely spent, I felt as if I'd been through the wringer with all these people's journeys. It's quite emotional and a lot of it is quite high-octane stuff."

Was she pleased to be able to use her Scottish accent, then?

"Well, it's funny, actually, everything I do now is with my accent," she quips. "I always have a laugh with Ricky Gervais, when I say 'What accent are you doing with that, Ricky?' and he's like, 'From Reading. What accent are you doing?' 'Scotland.'

"I could have done a Leeds accent, but I think there is kind of no need, really," she adds. "I mean, we live in such a cosmopolitan world, every city has got people from all over the place."

As for where Jensen will take her twang next, she's always been clear on one thing when it comes to her career and that is she doesn't have an agenda.

"In America, everyone had a five-year plan but I have never had a plan," she told the Telegraph last year. "I don't even know what I am doing tomorrow. I don't worry about the future. They will always need someone to play the old ladies with wrinkles."

Judging on recent moves, however, Jensen is sure to be - deservedly - front and centre.

Love, Lies & Records starts on BBC One on Thursday