Former French president Nicolas Sarkozy is to face trial on charges of illegally financing his failed 2012 re-election bid, according to prosecutors.

One of the two investigating magistrates in charge of the case decided that it should go to trial, a legal source told AFP news agency on Tuesday.

France probes Sarkozy over 2012 campaign funding

The prosecution claims Sarkozy spent nearly double the legal limit of $24m on his lavish campaign, using false billing from a public relations firm called Bygmalion.

It is understood that 13 other individuals will also go on trial over the so-called "Bygmalion Affair". 

Sarkozy's lawyer announced plans to appeal against the decision.

Bygmalion charged $16.2m in campaign events to Sarkozy's party - which at the time was called the UMP but has since been renamed the Republicans - instead of billing the president's campaign.

Sarkozy, who failed in a presidential comeback bid last year after losing to ex-Prime Minister Francois Fillon, has previously told investigators he knew nothing about the billing and put the responsibility squarely on Bygmalion and the UMP.

OPINION: Old Sarkozy does not match new France's needs

If convicted, Sarkozy, 62, faces up to a year in a prison. He could yet be spared trial, however, given that the second investigating magistrate in the case disagreed that Sarkozy be put in the dock.

Only one other president - Jacques Chirac - has been tried in France's Fifth Republic, which was founded in 1958. He was given a two-year suspended jail term in 2011 over a fake job scandal. 

Failed comeback

 Who is Nicolas Sarkozy?
Sarkozy was born in Paris in 1955 to a French mother and a Hungarian father. He regularly points to his mixed heritage, especially when he is criticised as anti-immigrant.
He joined the neo-Gaullist RPR party at a young age. After first being elected a councillor in the wealthy Paris suburb of Neuilly-sur-Seine aged 22, he became something of a protege of former president Jacques Chirac.
Sarkozy was named head of the RPR in 1998 and interior minister in 2002 following Chirac's re-election, and became head of the governing UMP party in 2004.
He was finally elected president in 2007. But in 2012, Sarkozy ended a five-year term mired in unpopularity.

The son of a Hungarian immigrant father, Sarkozy was nicknamed the "bling-bling" president for his flashy displays of wealth.

His trial will focus on whether he himself caused the overspending in 2012 by demanding that additional rallies be organised towards the end of his campaign, even though they were bound to blow the budget.

The judicial source said he was accused of having ignored two warnings from advisers in March and April 2012 about his spending, which came to "at least $45.7m".

While the so-called Bygmalion case is the most pressing, Sarkozy has been fighting legal problems on several fronts.

He is charged with corruption and influence peddling for allegedly offering to help a judge swing a plum retirement job in return from secret information about another case.

He has also been accused by former members of Muammar Gaddafi's regime of accepting millions in cash towards his first presidential campaign in 2007 from the toppled Libyan leader - claims he has vehemently denied.

After retiring from politics following his 2012 defeat by the Socialist Party's Francois Hollande, he returned to take the helm of the Republicans and sought the party's presidential nod in this year's election.

In a surprise result, he was eliminated in November in the first round of a primary contest, trailing the eventual winner, Fillon, and Alain Juppe, another ex-prime minister.

News of Sarkozy's trial comes as Fillon faces his own scandal over parliamentary jobs for his family.

The presidential candidate apologised on Monday for employing his wife for more than 15 years as an aide - which is legal - but continued to deny the more serious allegations that she barely worked for her average monthly salary of around $3,950.

Source: Al Jazeera and news agencies