South African opposition politician Julius Malema has been sentenced to five years in prison after being found guilty of the illegal possession of a gun and firing it in public.

Malema's lawyer said he would be appealing against the decision to prevent the leader of the Economic Freedom Fighters from being taken away to prison. The length of the sentence could see him being disqualified as an MP.

Standing in court in a dark suit and red tie, Malema showed little emotion as the magistrate read out the sentence.

Last year, he was convicted of five offences, including the unlawful possession of a firearm and ammunition, discharging it in a public space, and reckless endangerment.

The charges related to an incident in 2018 when a video emerged showing Malema using a semi-automatic rifle to fire several shots in the air during his party's fifth anniversary celebrations held in the country's Eastern Cape province.

In his defence, Malema told the court the firearm was not his and that he had fired the shots to rouse the crowd, South African news site SowetanLIVE reported at the time.

After being found guilty last October, Malema told his supporters outside the court in East London that "going to prison or death is a badge of honour".

"We cannot be scared of prison [or] to die for the revolution. Whatever they want to do, they must know we will never retreat."

He also vowed to take a challenge to the judgment to South Africa's highest court, the Constitutional Court.