A court in Turkey has sentenced the mayor of Istanbul to more than two-and-a-half years in prison for insulting public officials in a speech.

Ekrem Imamoglu was accused of the offence after saying those who annulled local elections in 2019 were "fools".

Imamoglu, 52, beat a candidate from Turkish President Recep Tayip Erdogan's AK Party to claim the city's mayoralty.

His conviction may disqualify him from holding political office or standing in next year's presidential election.

Imamoglu, from the secular Republican People's Party, is seen as one of the opposition's strongest candidates to take on Mr Erdogan in elections which have to be held by next June.

The case centres on comments Imamoglu made after he narrowly won the March 2019 mayoral election.

The result was annulled following complaints from the AKP about voting irregularities and the election board ordered a re-run.

Imamoglu defended his use of the word "fools" to describe those who overturned the original result, saying he was responding to similar language used by Interior Minister Suleyman Soylu.

Imamoglu went on to win again when fresh elections were held in June 2019 by polling 770,000 more votes than his rival and ending 25 years of AKP rule in Turkey's largest city.

Wednesday's ruling will have to be confirmed by an appeals court but if it is upheld then it would mean Imamoglu will be out of the running in next year's presidential and parliamentary elections.

In a video statement released after the court's verdict, he dismissed the proceedings, saying that a "handful of people cannot take the authority given by the people".

Supporters of the mayor gathered outside Istanbul's council buildings after he called for people to gather and show their support, shouting "government resign" and "truth, law and justice".

Imamoglu is expected to appeal against the sentence and will continue in post, but the possibility he may be disqualified from standing in the presidential election will make it harder for Turkey's opposition parties to choose a candidate to take on Mr Erdogan.

Polls show the mayor of Istanbul is among a handful of opposition leaders who could beat the long-standing president in a head-to-head race.(BBC)