Now she's facing up to 20 years in jail, does Carla Bruni regret achieving her ambition of marrying a man with his finger on the nuclear button?

Casting her vote in France's knife-edge parliamentary elections last weekend with her husband, former president Nicolas Sarkozy, felt like a return to the glory days for Carla Bruni.

As ever the cameras were drawn to the former model, chic in a navy blazer and tailored dark slacks, rather than the diminutive — and disgraced — Sarkozy, the first ex-president in post-war France to have been given a custodial sentence for corruption.

Sunday's outing to a polling station close to the townhouse they share in the swanky 16th arrondissement, home to the city's wealthiest citizens, was a chance to show that despite their travails they are as involved in the affairs of state as they were when the strutting Sarkozy occupied the Elysee Palace and Carla was at his side as First Lady.

But to close students of the Italian-born former supermodel, now 56, whose coquettish behaviour and extravagant boasts have amused and infuriated Parisians for almost 20 years, all was not well.

Absent were the jaunty smile and impudent asides, gone too was the flirting with the cameras so often a part of a thousand photo-calls. All this and more, the posing and the pouting, were in place as recently as May's Cannes Film Festival.

Instead her expression was intense, troubled even. Her head was tilted downwards and her eyes hidden by sunglasses. Noticeably she was wearing headphones attached to a mobile phone which, it now transpires, she was using to keep in constant contact with her lawyers.

She was hoping this week was going to bring good news in the long-running legal case involving the man she married at the presidential palace in 2008 after a whirlwind 80-day romance. Their high-living extravagance — at the expense of France's hard-pressed taxpayers — saw her compared to Queen Marie Antoinette for demanding that fresh-bread makers be installed on the presidential plane and spending an eye-watering £660 every day on flowers.

Instead, on Monday and Tuesday she was grilled by examining magistrates assisted by judicial police, over corruption allegations that could yet see both her and Sarkozy jailed. At the end of this harrowing ordeal, Carla was told that she was being charged with at least two significant offences — witness tampering and fraud.

In the event of a conviction, both come with potential prison sentences of up to a decade, and this is doubled if there are aggravating circumstances which, in Carla's case there conceivably might be, because she is said to have 'participated in a gang of wrongdoers with a view to ­committing the offence of fraud. (There are a total of 11 ­defendants in the case so far, including the model-turned singer's husband.)

Ziad Takieddine, 74, a Franco-Lebanese arms broker (and uncle of Amal Clooney, the British human rights lawyer who is married to Hollywood star George Clooney) has claimed that Sarkozy accepted ­€5 million from Colonel Muammar ­Gaddafi, the late Libyan ­dictator, to fund his 2007 election campaign.

Takieddine, who has a home in Holland Park, West London, alleges that he was intermediary between the two.

Ms Bruni, who has been barred from being in contact with all those accused except her husband, has denied any involvement.

It is the latest twist in an astonishing saga that has kept the smart salons of Paris aflame with gossip for years with its allegations of shady businessman, bent judges, corrupt politicians, unlisted 'ghost' telephones and suitcases stuffed with banknotes.

Hovering over it all has been the glamorous figure of Bruni, who liked to style herself as a 'tamer of men' and of whom it was said she'd had 30 lovers before marrying Sarkozy, among them famously, Mick Jagger and Eric Clapton.

For a woman who has lived in a bubble of absolute privilege all her life, the allegations could not be more devastating. She previously described the indictments against her husband as a 'senseless witch hunt' and 'incredible lies' that she was convinced would disappear.

But they did not go away. Her ­husband went on to be convicted, although he served his custodial sentence at home wearing an ­electronic tag for a year.

Now she is accused over a criminal conspiracy to 'whitewash' him for the Gaddafi cash and her involvement in what has been dubbed 'Operation Save Sarko [from jail]'.

'Carla's life has been turned upside down by these accusations,' said a friend who has known her since she arrived in Paris as a teenager. Her family settled in France after her father, a rich Turin industrialist, feared they would be kidnap targets of Red Brigades terrorists in the 1970s.

'She is first and foremost an artist – somebody who is concerned with beauty and love, and not crime,' added the friend.

'She has stopped eating and is finding it very hard to sleep right now — she has no idea when all of this is going to end. She's even started smoking again.'

Carla was often photographed smoking long menthol cigarettes for years, but officially gave them up just before giving birth to her and Sarkozy's daughter, Giulia, now 12.

Her legal fate now lies in the hands of the Paris judges presiding over the most serious presidential scandal in the history of the Fifth Republic, not least because of its international consequences.

Sarkozy was president when French and British air force jets bombed Libya in 2011. That ended with Gaddafi being hacked to death by a mob of his own ­subjects. 

It is tempting to wonder if Carla Bruni has any regrets about becoming a politician's wife and being so captivated by the ­aphrodisiac of high office.

'I want to have a man who has nuclear power,' she is said to have told a friend after watching Sarkozy on a TV programme shortly before they met.

So it was Sarkozy's finger on the atomic button that made up for his podgy and — significantly — short Napoleonesque-stature. He has never been allowed to forget the five inches that separate them, he a modest 5ft 5in, she a graceful 5ft 10in.

When a magazine cover ­purported to show a holidaying Sarkozy taller than his wife, ­commentators gleefully leapt on the image, mockingly accusing the couple of spending the ­vacation in their favourite pursuit of 'photo-shopping'.

This was one of the milder barbs about a relationship no one predicted would last. Soon after meeting the then twice divorced president, Carla dumped her previously left wing politics and brushed off some of her more lurid aphorisms, such as 'monogamy bores me' and that marriage was a 'trap'. Hardly ideal qualities for a potential First Lady.

For his part, Sarkozy was unveiled as a drooling lothario so captivated by Bruni's pert breasts, he allegedly shared his enthusiasm for them with his entire cabinet.

The only good news for Bruni from this week's charges is that the ruling does not prevent her from being apart from her ­husband. She once wrote a song about separation in which she sang of 'suffering and secrecy'. It was in response to being parted from Sarkozy for just five days.

'I obviously couldn't live without him,' she said. 'I would rather die before him'.

With a 13-year age gap, such a possibility is probably unlikely but it goes to the heart of their romance which began as a coup de foudre in late 2007, after meeting at a Parisian dinner party.

Not only had Sarkozy, who had just gone through a humiliating divorce — he had been dumped by his second wife Cecilia after she began an affair — asked for Carla to be on the guest list, he had insisted on sitting next to her.

'I don't want to be impolite,' he told his hostess, 'but I have to turn my back on you.' And he did as he turned his gaze and complete attention to the lissom, blue-eyed Bruni.

At the end of dinner he offered her a lift but declined her invitation to come up to her apartment for coffee. 'Never on a first date,' he told her.

While many French men were astonished by his apparent brush-off, Carla was charmed by his refusal. According to accounts, their affair rapidly escalated, after bombarding her with flowers, texts and gifts from Hermes, Sarkozy began to woo her over candlelit dinners in the Elysee Palace, reputed to have one of the best cordon bleu kitchens in France. There were also weekends at the presidential retreat of La Lanterne near Versailles and romantic trips to Morocco.

When news of the romance broke, with choreographed photographs of the couple visiting ­Disneyland Paris with their respective young children from previous relationships, France was both appalled and obsessed.

Carla's love life was legendary. The story of her entanglement with Jagger when she was just 22 was notorious — dumping Clapton who had begged his fellow rocker to keep away from her, along the way.

Their seven-year on-off affair ended the Rolling Stones' singer's marriage to Jerry Hall, who famously administered some Texan justice when she met Bruni at party by kicking her in the shins. The leggy blonde even made a shampoo commercial that many believe was aimed at brown-haired Bruni.

'This is for you, honey,' Jerry drawled in the advert, talking as if to Mick. 'And to think you thought you'd be better off with a brunette.'

Carla, who was unmarried until she met Sarkozy,, disdainfully let it be known that she thought Jerry had no 'class'.

In 2001 Carla, whose previous loves included Oscar-winning star Kevin Costner, the Swiss actor Vincent Perez and, improbably, Donald Trump, had a son with philosophy professor Raphael Enthoven. Again it was not straightforward — she had ­previously been the mistress of Enthoven's journalist father Jean-Paul.

Another fling, celebrity lawyer Arno Klarsfeld said she was 'a real tigress'. Sarkozy, however, needed not just a lover, but a wife. He had an upcoming State visit to Britain where he would be a guest of the late Queen at Windsor Castle. Travelling with a partner to whom he was not married would have been unthinkable.

As First Lady she purred and preened and cared little for social niceties. It was once luridly reported that she and her ­husband had kept the Queen waiting while they had a romantic moment. Sex, she said, was always very important. 'My husband and me were made of desire,' she announced. 'We wouldn't last without desire for each other. He's very passionate, more passionate than me.'

Despite rumours that both had strayed — she once said 'I told him if he cheats on me I'll cut his throat' — the marriage has survived.

In recent years as her husband has been ensnared in scandal after scandal, Carla has never once retreated from promoting herself and her love of music which she got from her concert pianist mother Marisa. Nothing is ever off limits.

Even the discovery that the man she called 'papa' was not her biological father, helped explain why, as she put it, she had been 'complicated and anxious' as a teenager.

After Swiss finishing school and beginning a course in art and architecture, she abandoned her studies for modelling. Her bottom was on the Guess jeans posters and she was the face of Karl Lagerfeld, Yves Saint Laurent and Versace. At her catwalk height she was earning £6 million a year.

She will need every bit of the resilience she learned, first as an international supermodel and then as a president's wife to fight these highly damaging and potentially humiliating allegations. According to friends she is made of stern stuff, overcoming a breast cancer diagnosis and a fraught childhood amid the threat of violent abduction.

The evidence against her — which is untested in court — is lurid and includes claims that she used a media fixer who once tipped off the paparazzi on her behalf, in an attempt to get Takieddine to drop his accusations.

But French justice rolls slowly, with plenty of time for yet more secrets to emerge from Sarkozy and Bruni's colourful and ­controversial lives.