THEY struck on a Wednesday afternoon, just before school was out and with a camera crew in tow. Amanda Hird answered the door of her Bishop Auckland home in her black velour tracksuit bottoms, with bleach stains down one leg and her two-year-old daughter wrapped around the other. It is possible she had baby sick on her blue sweatshirt, but she can't remember exactly.

Standing on her doorstep were television's no-nonsense style queens Trinny Woodall and Susannah Constantine of What Not To Wear fame.

"I looked awful," recalls Amanda, 36, with a shudder. "I didn't have a scrap of make-up on and I had a two-year-old hanging around my ankles and a baby in one arm. Then my friends came round and I realised I'd been set up."

Unlike most of Trinny and Susannah's 'victims' who are nominated for a style overhaul by friends and family, Amanda had initially responded to a request by producers, who wanted to find women in the North's manufacturing industry who were dreading going to their husband's Christmas office party. But after not hearing anything for months, Amanda had forgotten about it.

"I actually convinced myself that the reason I hadn't heard from them was because I dressed so well - but boy was I in for a surprise," she admits.

Unbeknown to her, Trinny and Susannah had already been along to her workplace, watercooler company Ebac in Bishop Auckland, where she is the operations director. The pair quizzed all her colleagues on what they thought of Amanda's dress sense before doorstepping her at home and rummaging through her wardrobe.

"I didn't realise until they started going through my wardrobe how dark all my clothes were," she says. "If I had a party to go to I would either reach into the wardrobe and pull out something I'd worn thousands of times before, or go over to my mum's and borrow something from her wardrobe - that was one of the bits they hated, particularly as my mum is a completely different shape to me.

"Basically, I thought that I dressed OK. If there was something important happening then I would make the effort."

If Amanda thought being pounced upon on her doorstep was humiliating, that was nothing compared to Trinny and Susannah's notorious mirrored cubicle. The door banged shut and Amanda was left staring at her reflection from every angle in her old navy blue and grey dress.

"It was horrible," she recalls. "I'd always felt the bee's knees in this dress. When I looked at it I thought 'yes, it's quite slimming', but it didn't do anything for the top half, for my sausage arms or my height, as I'm quite small. I'd just been choosing clothes to hide my kangaroo pouch."

To make matters worse, the pair whipped off her dress in front of the television cameras, before she had time to change her underwear. To her horror, her mis-matched bra and knickers were exposed to the nation.

"I was standing there in a black bra and white pants and stiletto heels - I looked like a prostitute," laughs Amanda. "And in mis-matched underwear!"

It is hardly surprising Amanda had little time for herself prior to the programme, being mum to Sara, nine, Emma, eight, and Alex, two. She is also wife to Tony, who's MD of Bottled Water Direct, part of the Ebac group, and works full time. But she came to realise throughout the programme that her appearance mattered and that it was important she made time for herself.

"You convince yourself you haven't got time to exercise, you haven't got 'me time' but if you do then what you give your kids and everyone is much more positive," she says.

The programme is notorious for probing beneath the skin, whittling out insecurities and childhood issues in front of the cameras, before the surface appearance is transformed. It can be a raw process for the people taking part and Amanda was no exception.

"I'm quite boisterous really but if I was at a party, I would be the one washing up in the kitchen or playing with the kids out of the limelight," says Amanda. "I felt overweight and convinced myself that I was bigger than I was and I lacked confidence. I found doing the video diary hard because I didn't really want to talk about my feelings on television, but then I thought, if I don't talk about them, maybe I'm not dealing with them."

Another difficult moment comes when the 'victims' have to watch a videotape of their work colleagues and family talking about their dress sense and overall style. Amanda felt very emotional as she watched the tape. Her colleagues told the camera that she wore dark clothes a lot and didn't seem to smile much. They also took exception to a red anorak she used to wear.

"I got very upset," she says. "It wasn't that I was hurt, it was that people were talking like they cared about me," she says.

Amanda had to go to London for filming every Wednesday for four weeks during October. She says Trinny and Susannah would often play up for the camera, prodding and poking her, but that for every harsh comment, came two positive ones.

"They were actually very sensitive, especially Trinny," she says. "They gave me a set of rules to follow: that it isn't wrong to have a bit of cleavage on show, that I shouldn't wear anything too long or short because of my height, that I should wear round-toed shoes because I have slim ankles and that I should never over-accessorise."

Amanda was whisked off to Selfridges in London with Ingrid Tarrant, the wife of Who Wants To Be A Millionaire? presenter Chris, who will also appear on the programme getting ready for an awards ceremony.

Amanda was told she could choose one glamorous outfit for the launch party of Ebac's new luxury Waterfall Spa in Leeds. Although she was reluctant to wear the turquoise two-piece which had been picked, when she put it on, she realised Trinny and Susannah had been right about it suiting her. She walked down the pink carpet towards the spa entrance feeling like a new woman.

"I went from being a supporting actress to the leading lady," she says, glowing with pride. "Tony was gobsmacked. He couldn't believe how different someone could be with some good make-up and a new set of clothes. But it was the confidence inside as well. He had never said anything about the way I dressed and was never embarrassed by me, but just thought I could have looked better."

Today, days before the programme is due to air, Amanda is sitting in Ebac's boardroom dressed in a soft wool orange wrap cardigan, a brown embroidered skirt and brown suede boots. She looks chic, confident and co-ordinated.

She has followed Trinny and Susannah's rules since the filming and has thrown out her red anorak and the grey dress. She feels more confident in life and her love life with Tony has also been given a boost.

"It was certainly a life-changing experience. It changes the way people look at you," she says. "They gave me confidence. They made me look at my body and made me realise that it wasn't as bad as I thought it was. Tony and I probably talk to each other more now and focus on what's important. It's about your whole persona, and rightly or wrongly, your personality is reflected in what you're wearing."

But will the feelings last? Is there any chance that Trinny and Susannah may turn up on her doorstep in a year and catch her in those black velour tracksuit pants again?

"I'm hoping that because they've gone to ITV that they won't be coming back again - but then you can never be too sure," she laughs. "How I'll be next October I don't know. But I do know how good clothes can make you feel and how much more confident they can make you."

* What Not To Wear...When You're A Plus One is on BBC1 on Friday at 8.30pm.