The Workers’ party in Brazil named jailed former president Luiz Inácio Lula da Silva as its nominee for the country’s top job.

Delegates of the left-leaning party confirmed Lula, who served two terms as Brazil’s president between 2003 and 2010, with enthusiastic approval at a convention in São Paulo on Saturday.

Since April, the former president has been jailed on a corruption conviction, but he denies any wrongdoing and claims he is being politically persecuted.

Although his popularity has dropped slightly, Lula leads polls for the office by a large margin. Surveys also suggest voters would lend their support to another Workers’ party candidate if he is barred from running.

It is unclear who would replace him if that is the case, and the party is not expected to name Lula’s running mate until Monday.

In a recorded message to the convention, Lula said: “It is those that sentenced me that are jailed in a lie”.

“Brazil needs to restore its democracy, find itself and be happy again,” he said. “They might lock me up, shut me up, but I will keep my faith in the Brazilian people.”

The Workers’ party chair, Gleisi Hoffmann, who is trying to lure other left-leaning parties to the ticket, addressed supporters at the convention.

“They tried to exclude Lula from the political discussion,” she said. “There is no political discussion in Brazil without Lula and the Workers’ party.”

The right-leaning candidate Geraldo Alckmin of the Brazilian Social Democracy party and the centrist Marina Silva of the Sustainability Network party were also nominated by their parties on Saturday.