That's one way to promote your book! Tulisa shows off her cleavage in all its glory as she leans forward during autobiography signing

PUBLISHED: 01:27, 28 September 2012 | UPDATED: 10:13, 28 September 2012

It was only a couple of days ago that she attempted to go for the butter wouldn't melt look in an angelic white dress to one of her book signings.

And on Thursday morning she even looked classy as she showed up to record a number of radio interviews across London dressed in jeans and a cream knitted jumper.

But on Thursday night Tulisa Contostavlos caused quite a stir as she reverted back to her skimpy dresses - and gave quite the eyeful as her curves were well and truly on display.

Cleavage alert! Tulisa Contostavlos gives fans an eyeful as she bends down as she sits at her book signing in Milton Keynes

Cleavage alert! Tulisa Contostavlos gives fans an eyeful as she bends down on her seat at her book signing in Milton Keynes

The N-Dubz star was in Milton Keynes this time to promote her tome, Honest: My Story So Far.

And she dressed to the nines, clearly in the mood for a girlie number as she wore a black and white frock with studded detailing on the strapless top with a sweetheart neckline.

On first sight it was only Tulisa's legs that were on full display as she finished off her look with strappy black shoes and her bleach blonde locks worn down in tumbling waves.

That's better! She opted for a black and white frock with stud detailing and managed to keep her curves intact when she first showed up for some photos

Curves on display: The N-Dubz star was promoting the release of her autobiography, Honest: My Story So Far, in Milton Keynes on Thursday afternoon

Taking her seat: The X Factor judge seemed unaware quite how much flesh she was displaying as she adjusted herself on the seat

Taking her seat: The X Factor judge seemed unaware quite how much flesh she was displaying as she adjusted herself on the chair

But when she sat down to take her seat, ready to sign her books for the waiting fans, Tulisa gave them more than they bargained for as she pulled herself forward, thus leaning down to reveal her cleavage.

The X Factor judge seemed unaware she was showing off quite as much flesh as she was as she prepared herself for the lengthy meet and greet session.

Once she was perfectly in place, Contostavlos still showed off her curves as she sat down for the event, but not quite as much as when she first readjusted herself in the chair.

All dressed up: Earlier this week Tulisa went for more angelic numbers as she wore cutesy frocks to her other signings and promotional sessions

Pen at the ready: She sat ready to scribble her autograph and chat to her fans who were patiently waiting to get their hands on a copy of the tome

It was only a few hours earlier that she stunned for a different reason - for actually covering up in a classier number of jeans and a jumper for her promotional schedule.

On Thursday morning the singer turned up to record an interview on BBC Radio 1 in London.

She completed her look with a cream knitted jumper with studded detailing on the shoulders.

Tulisa finished off the outfit with some black platform wedges, which also had studded detailing, while she wore sunglasses to cover her eyes and wore her bleach blonde locks again down and curled.

It was just one of her radio slots she completed on Thursday morning as she also showed up to Capital FM.

Classier than usual: Tulisa Contostavlos shows up to the BBC Radio 1 studios covering up for once in a pair of jeans and a cream knitted jumper just a few hours earlier

Wholesome: Th X Factor judges decided to try out a different image from her skimpy dresses and tracksuits as she wore the autumnal get-up

Wholesome: The X Factor judge decided to try out a different image from her skimpy dresses and tracksuits as she wore the autumnal get-up on Thursday morning

And it was during that interview that she pleased fans by revealing she's planning to reunite with her N-Dubz bandmates next year following a hiatus.

And the discussions started when she visited cousin and bandmate Dappy at his house several days ago.

She told the station: 'I was with Dip Daps the other day and I was around his house having a little heart to heart.

Strike a pose: She greeted fans outside and posed for pictures in the comfortable get-up

'We got all emosh and said that we miss being in the band. We're lonely as solo artists and let's reunite next year. So we're going to do it.'

While she's been busy promoting the current series of The X Factor, where she returns for her second stint as a judge this year, she's also been launching her new explosive autobiography.

The tome documents her teenage drug-taking and losing her virginity at the tender age of 14.

But Tulisa looked positively angelic as she attended a book signing for Honest: My Story So Far in Kent on Wednesday afternoon, the day before her radio schedule.

With her cute smile and girlie white dress, the 24-year-old singer screamed sweet and innocent as she met fans at the Bluewater Shopping Centre - a far cry from the Young hitmaker's usual sexy street style, and the look she has now gone for.

Angelic: Tulisa Contostavlos went for a sweet and innocent look as she promoted her new book, Honest, at Bluewater Shopping Centre in Kent on Wednesday