Pauline Quirke is still the down-to-earth, 'cor blimey' Londoner who won the hearts of the nation as Sharon in the hit comedy series Birds Of A Feather.

It's just that physically, there's a lot less of her.

Twelve months ago, when she was a size 28, tipping the scales at almost 20 stone. Nowadays, at 5ft 6in, she weighs 12 stone 4lbs and wears a dress size 14.

Pauline, 52, who suffers from osteoarthritis, says that a hip replacement in 2009, aching knee joints and a fall in which she broke her arm, were among a series of catalysts which led to her decision to slim down.

"Steve [her husband and agent] knew I was upset about the hip. He could see me getting bigger and bigger. Professionally and personally I was very happy, but the hip was the beginning of it."

Her weight has never slowed down Pauline's career as her role as Hazel Rhodes in Emmerdale proved and her successful Pauline Quirke Academy, which runs all over the UK including Southend and Wickford.

However, constant tiredness, no exercise, feeling generally unhealthy and the difficulty she had managing day-to-day events such as buying clothes sent Quirke into an all-time low.

Other humiliating incidents spurred her on, such as the time she and her family went on holiday to Mallorca and she couldn't buckle her seatbelt on the aircraft.

She had to request a seatbelt extension that arrived in an eye-popping shade of fluorescent orange.

"I dreaded getting on an aeroplane. I used to think, 'Will it go on this time?' I could always wangle it by lifting up my belly and doing up the belt, but sweat would be pouring off me and my table would never go down. I just couldn't get it done up this time.

"I like to make it a funny story, but it wasn't."

She recalls the humiliation she felt in her new book, Where Have I Gone?, which charts her weight loss.

"I saw the see-through stewardess making her way back towards me, brandishing the fluorescent orange belt aloft and checking row by row and seat by seat for a woman with a baby without a seatbelt.

"When she finally spotted me - not a toddler in sight - I saw pity in her eyes... and I wanted to die."

So, Pauline went on the LighterLife diet, a food replacement programme where normal meals are substituted with low calorie packs of powder mixed with water. She didn't eat normal food for eight months, but lost seven stone in half a year.

At the time, she was living in Leeds, working on Emmerdale and initially she'd privately have her replacement meals while the rest of the cast went to the canteen.

The weight came off so dramatically that it was even worked into the Emmerdale script, as it has been in the 17-week Birds Of A Feather theatre tour, which began earlier this month.

"We've kept a few fat jokes in because I'm still fatter than Lesley [Joseph]. She's lost 16lbs, Linda's lost three and a half stone and I've lost eight.

"There's a great line when Dorian says, 'Oh Sharon, you've lost weight. What was it? Bypass? Gastric band? Dyno-Rod?'"

Today Pauline reflects that her initial target of 11 stone was going a bit too far. The lowest she's been during the diet is 11 stone 13lbs.

"I remember trying on something that was a size 14 and it was too big. I thought I'd gone far enough. I never wanted to push this to the extreme. It was about being healthy and feeling well.

"I'd like to stay between 12 and 12 1/2 stone. Every week I'll weigh myself just to keep an eye on it and will have the packs as part of my life.

"But I don't want to spend the rest of my life being frightened of what I want to eat. You can have a slice of cake, but not every day."

She's confident she'll not put the weight back on, as counselling has helped change her attitude to food, she says.

Today, she's joined a gym and enjoys clothes shopping. She is eating normal food - porridge for breakfast and mainly fish in the evening - but still regularly uses the meal substitute packs.

"I can't remember the last time I peeled a potato and it's given me a great sense of freedom," she says with a smile.

She wouldn't dream of having surgery to remove any folds of loose skin left by the weight loss, though.

"I'm 52 - it was never going to all ping back. I won't be doing bikini shoots in the near future but it's not as bad as one would have imagined."

Pauline first appeared on screen aged eight in Dixon Of Dock Green and gained later critical acclaim for performances in Down To Earth and The Sculptress.

But it was the sitcom Birds Of A Feather which ran from 1989 to 1998, in which she starred with her lifelong pal Linda Robson and Lesley Joseph, which brought her the most recognition.

When the idea of reuniting the three women for a theatre show arose, she hadn't been on the stage for more than 20 years.

But with her children grown up - Emily is 27 and Charlie 17 - there was nothing stopping her, she reflects, although her lifelong stage fright remains.

"I went through 101 episodes of Birds Of A Feather not sleeping the night before filming them and vomiting before the actual taping."

Her son, Charlie, will also be in the stage show, sharing the role of Travis, Tracy's son, with Robson's son, Louis.

"As Charlie's there as well, I don't want him to see how nervous I get, hyperventilating or being sick. I've spent most of my professional life terrified.

"It doesn't make any difference if it's live or recorded. What gets me going is the audience."

Sounds like a good omen for keeping the weight off, at least.

Pauline and the rest of the cast will star in Birds of a Feather at the Cliffs Pavilion from March 12 to17.

She will also be in Southend to sign copies of her new book, Where Have I Gone? at the Victoria Shopping Centre in Southend 16 March at 12.30pm.