I'M fidgeting in my chair, loathe to scratch my itchy nose, in case Darren Stanton starts to analyse what it means.

Interviewing an expert in body language and self-styled human lie detector is making me unnaturally edgy.

Darren, from Carlton, is the man who analysed the body language of the three political leaders in the pre-election televised debates last year and unearthed the traits they showed when under duress.

Darren says: "Cameron was very well rehearsed, very slick. I picked up that when he was under stress he licked his lips, which he still does now.

"When he was saying things he wasn't confident about or committed to, he would gesture with his hand and take a step back."

Gordon Brown, on the other hand, repeatedly picked his thumb nail when pressured.

"Clegg came out on top, talking to the audience at home rather than just the studio.

"He wasn't that rehearsed and hadn't done a great deal of preparation. He seemed the most genuine," said Darren.

The media clamoured over his analysis and it proved a turning point for Darren, who quit his job as a constable with Derbyshire police six months ago to focus on his career as a mind and body expert.

As well as body language and lie detection, the 38-year-old specialises in hypnosis, motivational speaking and helping people achieve their dream.

He has condensed his wisdom into his first book, Project Jam Jar – the title coming from an experiment he observed with fleas.

"If a flea is on a table it will jump to the ceiling of the room. But if it is placed in a jam jar, after a few hours it will learn not to keep jumping high as it's stopped by the lid. So it starts to take just tiny jumps.

"If it's then taken out of the jam jar it will continue to make only the tiniest of jumps. It has learned not to bother jumping high as there's no point.

"I think it's a powerful analogy for us as human beings.

"Most of us allow society or our families and friends to set limitations for us when the reality is we can achieve anything we wish."

Following his own advice and quitting the police to follow his true interest, Darren is now about to embark on a national tour of seminars and book signings, including several dates in Nottingham and Mansfield.

He spent three years as a police constable and, before then, 15 years as a special constable in Notts.

As an expert in the unconscious signals we give off when lying, was he tempted to use this technique when interviewing suspects?

"I guess I did because it's part of who I am but none of that would be admissible. I could not introduce that into the evidence.

"But it was about 80 per cent accurate."

Telltale signs that someone is telling a porkie – whether it's your partner or at a job interview – are a pale face, blushing and mirroring your interrogator's language.

"If you ask your partner 'have you been to the pub instead of the gym? they will reply, 'No I didn't', if telling the truth. If lying they will say 'No I didn't go to the pub instead of the gym', mirroring your language. This is called a contraction."

I'd better watch what I say as well as how I'm sitting, where I put my arms, whether I fiddle with my hair and even where I glance.

"Right-handed liars tend to look right," says Darren, who was asked to write the top ten tips for spotting a liar by The Sun following the end of Cheryl and Ashley Cole's marriage.

As I look him straight in the eye, he tells me not to worry as unlike the politicians, he is not analysing my every move although he can tell I'm passionate in what I do.

His exciting plans for the future include filming a pilot for a possible new Channel 4 television show featuring a homeless girl, a Big Issue seller and a woman who has lost a high-powered job.

By putting them through a 28-day process of life-changing techniques, Darren hopes to prove that they can achieve whatever they desire.

"Not everyone wants to be a millionaire or Richard Branson.

"It could be just a better salary or a different partner," he says.

Darren will be signing copies of his book, priced £9.99, at WH Smith in the Victoria Centre on April 16 at 2pm and May 14 at Waterstones in Bridlesmith Gate at 11am.

Fans will be able to have a consultation with him at the Mansfield Show on May 7-8 at the Civic Centre.

For more information, visit www.DarrenStanton.co.uk