Brazil's former president Lula fights for freedom as he marks one year in jail

Since entering prison a year ago, Brazil's former president Luiz Inacio Lula da Silva has been spending his days working out in his cell and fighting to prove his innocence.

The 73-year-old leftist icon, who has been sentenced to 25 years behind bars in two separate corruption cases, remains determined to challenge the "injustices" he has suffered, said Gleisi Hoffmann, head of the Workers Party that Lula founded.

"From the political point of view... he remains strong," Hoffmann said as Lula prepares to mark one year in jail in the southern city of Curitiba on Sunday.

Lula has denied all the charges against him, claiming they were politically motivated with the aim of preventing him competing in elections last year that were won by Brazil's new far-right President Jair Bolsonaro.

During his election campaign, Bolsonaro said he hoped Lula would "rot in prison." Lula has been allowed to leave jail twice in the past 12 months -- once for the funeral of his seven-year-old grandson, whose death Hoffmann said had left the former president "shattered, very sad." The other time was to give evidence in court.

Lula, who served two terms as head of state between 2003 and 2010, also spends time reading and writing letters that his party publishes, and watching his beloved Corinthians football team from Sao Paulo on television.

But the news brought to him by his lawyers on their daily visits could not be worse. Everything they have tried so far to free the popular leftist leader has failed.

On Thursday, Lula suffered another setback when the Supreme Court indefinitely delayed debate on whether a prisoner convicted of a non-violent crime should be released before the end of their appeals process, which could have potentially freed him.

Lula is running out of options.

He is awaiting the outcome of a second appeal to review his first conviction on bribery and money laundering charges, which put him jail in the first place for just over 12 years.

But Silvana Batini, a prosecutor and law professor at the Getulio Vargas Foundation, said his chances of success were slim.

"The rates of alteration and reviews of convictions are low, statistically speaking," said Batini.

But she added: "Obviously, the question of Lula is exceptional." Lula is also appealing the second sentence of almost 13 years handed down in February for accepting renovation work by two construction companies on a farmhouse in exchange for ensuring they won contracts with the state-run oil company Petrobras.

Bolsonaro's victory in October's elections ended decades of center-left rule in Brazil and delivered a major blow to Lula's chances of freedom.

Soon after winning, Bolsonaro named Sergio Moro, the anticorruption judge who handed Lula his first conviction, as justice minister. Representatives of the Workers Party are expected to join dozens of Lula fans on Sunday who have maintained a vigil at the prison gates since the politician was jailed.

They hope to breathe new life into the flagging "free Lula" campaign.