Sarkozy in the dock: As the former French president faces corruption charges over 'suitcases of cash from Gaddafi', why the sensational claims are set to reignite interest from around the world

When France's president Nicolas Sarkozy and his supermodel wife of two months, Carla Bruni, arrived in Britain for a state visit in March 2008 they were feted as Gallic royalty.

The newlyweds stayed at Windsor Castle and had a private lunch with the Queen and Prince Philip before Sarkozy travelled to Westminster to address both houses of Parliament.

That evening, at a grand banquet in St George's Hall, he raised a toast to 'the brotherhood of the French and British people', while Her Majesty did her own bit for the entente cordiale by bestowing him with an honorary knighthood.

Such a splendid occasion will today seem a very distant memory to the man universally known as 'Sarko'.

This morning, the 69-year-old will take his place in the dock at Paris's principal criminal court sporting an electronic tag on his right leg.

Sarkozy, who was convicted in December of trying to bribe a judge, now confronts his most serious charges to date: corruption, illegal campaign financing, benefiting from embezzled public funds and being party to a criminal conspiracy.

In a trial listed to last no less than three months, prosecutors will claim that he accepted money-laundered funds from Colonel Muammar Gaddafi, the late dictator of oil-rich Libya, totalling tens of millions of pounds.

The cash reportedly helped finance the 2007 election campaign which swept Sarkozy to power, meaning that his victory will be for ever tainted by the allegation that it was based on dirty money from North Africa.

If found guilty, the man who was nicknamed 'President Bling-Bling', thanks to his penchant for the high life, faces up to a decade in prison.

And his wife could suffer a similar fate. Carla, 57, is accused of being part of a £4 million campaign dubbed 'Operation Save Sarko', a complex and illegal plan to try to keep her husband out of jail.

She has been charged with a range of corruption offences, including 'witness tampering in an organised gang', and her trial is expected to get under way later this year.

This is all a far cry from the days when Sarko was billed as the poster boy of French conservatism and I used to interview him regularly as a journalist and author based in Paris.

He projected himself to me as a Margaret Thatcher-style reformer who would liberalise the French economy, just as the Iron Lady did in Britain in the 1980s.

The pace at which he worked to bring about change earned him the nickname 'Speedy Sarko' – and he didn't hang about when it came to his personal life either.

He became the first French president to divorce his wife while in office. A break-up with Cécilia was always on the cards, given that they were both known for their illicit affairs.

Indeed, Nicolas and Cécilia were both married to other people when they first got together. He was with his first wife, Marie-Dominique, and Cécilia's husband was a French TV chat-show host called Jacques Martin, a kind of French Bruce Forsyth 24 years her senior.

Sarkozy got to know them on their wedding day because, as the mayor of the chichi Paris suburb of Neuilly-sur-Seine, he conducted the ceremony. Though 29 and married, Sarko later admitted that after laying eyes on the beautiful bride for the first time, he asked himself: 'Why am I marrying this woman to someone else? She is for me.'

The two couples often went on skiing holidays together, and Sarko was rumbled when Marie-Dominique spotted footprints in the snow under Cécilia's window.

Cécilia was briefly France's First Lady when Sarkozy entered the Élysée Palace in 2007, but her days were numbered from the outset as she was known to be seeing a French-Moroccan businessman, while her husband's conquests at the time included a political journalist on the centre-Right daily Le Figaro.

As a result, Sarkozy's five-year term took on the status of a wild soap opera, which reached its climax when he wooed Bruni, an Italian heiress and self-styled 'tamer of men', whose past lovers included multimillionaire celebrities such as Mick Jagger and – it was rumoured – Donald Trump.

Sarko himself revelled in the high life and thought nothing of borrowing super-yachts and private jets from billionaire industrialists, while treating them to lavish meals at Michelin- starred restaurants.

After becoming Sarko's third wife, Carla soon turned into his Marie Antoinette, with presidential accounts revealing that she spent £660 a day on fresh flowers for the Élysée Palace.

With so much energy being expended on luxury living, many suggested that sucking up to the super-wealthy had become Sarkozy's priority – an accusation that was given added credence when the hugely controversial Gaddafi rolled into Paris in December 2007.

Sarko had invited the so-called 'Brother Leader' for a red-carpet state visit and the Libyan despot was even given permission to pitch his tribal tent in ornate presidential gardens by the Champs-Élysées.

This sort of bromance was all the more inappropriate given that Gaddafi was linked to a range of atrocities, including the Lockerbie bombing, which saw 270 people die when a PanAm flight en route to New York went down over Scotland in 1988, and the shooting of Metropolitan police officer Yvonne Fletcher by a gunman inside Libya's London Embassy four years earlier.

Even Sarko's own Human Rights State Secretary, Rama Yade, said France 'was not a doormat' for Gaddafi to 'wipe off the blood of his crimes'. But Sarkozy just shrugged his shoulders, knowing that his presidential immunity would protect him from investigation.

This all changed in May 2012, when he lost his first attempt at re-election to François Hollande. Within a day, Sarkozy's Paris townhouse was raided by the fraud squad – and he and his wife's troubles began in earnest.

For Gaddafi was not the former president's only problem. Sarkozy first came under suspicion of engaging in corrupt dealings when he was accused of accepting envelopes full of cash from the late L'Oréal heiress, Liliane Bettencourt.

While these claims did not stick – his lieutenants took the rap – Sarkozy was sentenced to three years for trying to get classified information about the case against him from a judge.

Telephone taps proved the prosecution case against Sarkozy, who was told he could serve a year with an electronic tag, while the other two were suspended.

He is currently appealing another prison sentence – this time of one year – for using false accounting to disguise illegal overspending in his failed re-election campaign of 2012.

Other ongoing cases include claims that he was involved in Qatargate – the successful but allegedly corrupt plan to stage the 2022 World Cup in Qatar.

But it is the Libya affair which will now reignite interest in Sarkozy around the world. It is primarily based on allegations by a Franco-Lebanese businessman called Ziad Takieddine, who once told French media that in 2006-07 he had personally handed over suitcases stuffed with banknotes to Sarkozy and his chief of staff, Claude Guéant (something the latter later denied).

Takieddine said the equivalent of at least £42 million was illegally poured into Sarkozy's 2007 presidential campaign.

A document signed by Libya's former chief of intelligence, Moussa Koussa, apparently proves the payment. Unfortunately for Sarkozy, like many witnesses from the time, Koussa is alive and well.

So, too, is Gaddafi's son Saif al-Islam, who told me he was one of 'numerous Libyans prepared to offer conclusive proof' of massive amounts of cash being given to middle men working for Sarkozy.

There is no love lost between the two men as it was Sarkozy who ordered the French Air Force, supported by Nato allies, to start bombing targets in Libya in March 2011 as a means of protecting civilian lives during the Arab Spring revolt. But regime change was clearly the desired result.

By the time Sarkozy and Britain's then PM, David Cameron, paid a triumphant joint visit to Tripoli in September of that year, the fleeing Gaddafi was close to being beaten to death by a mob.

A key question to be considered by judges is whether Sarko wanted Gaddafi dead because of his potential to produce incriminating evidence. There are claims, admittedly hotly contested, that Gaddafi was killed by agents working directly for the Sarkozy administration.

Sarkozy and Bruni deny all the charges and are determined to prove their innocence. Yet moves are already underway to strip him of his Legion d'Honneur and Order of Merit – France's highest civilian decorations.

As the first French president to be convicted for crimes carried out while in office, he 'has next to no chance of hanging on to them', a senior judicial source in Paris told me.

All in all, no one could blame Carla for ruing the day she met a charismatic politician with a taste for la grande vie.

• Nabila Ramdani is a French-Algerian journalist and academic and author of Fixing France: How To Repair A Broken Republic.