Her PR, even her detractors concede, has been brilliant.

Michelle Mone has sold a rags to riches story to the press for more than 20 years.

But the harsh business reality is that her bottom line has never quite had the lift of her much-hyped Ultimo push-up bras.

Ms Mone's lingerie empire - always far more modest than her publicity would suggest - effectively came to an end when she sold most of the business, ranked "small" by Companies House, amid substantial losses in 2014.

Now, most of her business interests gone, Ms Mone is the UK Government's start-up czar, charged with finding out how to encourage entrepreneurial zest in Britain's most deprived neighbourhoods.

But can her flair for getting pictures of her bras in to the papers serve as a model for enterprise for the urban poor?

After all, she has achieved some spectacular publicity coups.

She secured Rachel Hunter, former wife of Rod Stewart, as the face of Ultimo to replace the rocker's new wife Penny Lancaster.

And her firm's creations - while never having the financial oomph or commercial reach of competitors like Wonderbra - have generated acres of usually positive coverage.

Scottish business sources, however, are not convinced she has what it takes to find the answer to woefully low business start-ups in deprived parts of Britain.

"She can bluster," said an entrepreneur who knows her well. "But the truth is that her PR success is based on her ability to produce photos of girls in their undies for the tabloids."

Not everything said in the redtops about Ultimo has proved to be true.

Reports that the firm designed the cleavage-enhancing bra sported by Julia Roberts in Hollywood hit Erin Brockovich were dismissed by the film's makers.

Ms Mone sold most of Ultimo Brands - which took over the assets of her main company, MJM International, after it chalked up huge losses - to Sri Lankan business partners.

Company executives insist it was a going concern despite negative net worth.

She had built the business up with her husband, Michael, over two decades. Those familiar with Ultimo suggest she was the "face" of the firm and Mr Mone was the "head". The two split acrimoniously in 2011. MJM, which had been producing modest returns, suffered as a result.

Ms Mone found herself in the papers for the wrong reasons. Her firm was ordered to pay nearly £16,000 in compensation to a worker who found a listening device in a vase of artificial flowers in his office after an employment tribunal.

"It is not normal to bug your employees," said a senior business source. Ms Mone then detailed her account of her 22-year-long marriage's breakdown in a book. She described her regret for trashing Mr Mone's £100,000 Porsche, putting laxatives in his coffee and cutting up his clothes.

Ms Mone thought her husband had cheated on her with her head of design, Samantha Bunn. The pair have since set up home together but Mr Mone denies adultery. He has said her book was "a work of total fiction".

Such stories means worries about Ms Mone's appointment have spread from business in to politics, especially Conservative politics.

"There is deep, deep concern about this appointment in the Scottish party," a Tory source said.

Senior party figures north of the Border, meanwhile, are worried that Ms Mone's abrasive social media style could backfire.

During the 2011 London riots Ms Mone took to Twitter to call for the army to support police. "People who riot, steal, cover face deserve zero human rights," she said.

This was her tweeting about people from exactly the kind of community the Conservatives in Westminster now want her to help.

And she was doing so at about the same time she was admitting trashing her husband's car. "Michelle has become addicted to the adulation of strangers", said a former friend. But as she enters the world of politics, can she handle the criticism of strangers?