France's highest court has upheld a sentence against former French President Nicolas Sarkozy over the illegal financing of his 2012 re-election campaign.

He was found guilty of overspending on his campaign, then hiring a PR firm named Bygmalion to cover it up.

In 2024 Sarkozy, 70, was handed a one-year sentence of which six months were suspended, meaning they could be served by wearing an electronic tag instead of going to jail.

He has always denied all allegations.

Prosecutors in the case said Sarkozy's UMP party spent nearly double the €22.5m (£19.4m) cap on his campaign, splurging on lavish campaign rallies and events. To hide the costs, UMP then asked Bygmalion to invoice the party, rather than the campaign.

Today's ruling is the second definitive conviction for the former president, who was in power from 2007 to 2012. Last December the High Court of Appeal upheld a corruption conviction, requiring Sarkozy to wear an electronic monitoring bracelet for six months. In September, he received a five-year sentence for criminal conspiracy, spending 20 days in jail before his release earlier this month.

An appeal trial will be held next year, during which Sarkozy must remain under strict judicial supervision and is barred from leaving France.

Days after his release, his team announced that Sarkozy was writing a book about his experiences in jail, titled A prisoner's diary. An excerpt shared on social media describes the contrasts and introspection encountered during his incarceration.