SAO PAULO — Former president Luiz Inacio Lula da Silva, frontrunner in Brazil’s October presidential elections, was given 24 hours on Thursday to surrender to police and start a 12-year prison sentence for corruption.

The timing of the order from Judge Sergio Moro, head of Brazil’s huge "Car Wash" anti-graft probe, took Lula’s lawyers by complete surprise. They had been expecting to delay the start of prison at least until next week.

Moro said Lula, who lives near megacity Sao Paulo, must "present himself voluntarily" to police in the southern city of Curitiba, where the "Car Wash" probe is based, by 5pm on Friday.

The drama is of huge consequence to Brazil’s presidential race, in which 72-year-old Lula, despite his legal problems, is the easy leader in polls.

Currently, hard-right former army officer Jair Bolsonaro, who openly praises Brazil’s 1964-1985 dictatorship, is in second place.

In his first public reaction, Lula, who was once among the planet’s most popular politicians, called the abruptly announced order "absurd", CBN radio reported.

Asked if he would comply, the veteran leftist leader, who ruled from 2003-2011 and is seeking a third term in October, said only that he would act on his lawyers’ advice, CBN reported.

At a late night gathering on Thursday with his Workers’ Party leadership in a metal workers’ union building in Sao Bernardo do Campo, near Sao Paulo, Lula waved to a crowd of supporters from a window, video posted on his Facebook page showed.

The head of the union, Wagner Santana, said on a sound system that Lula "will not hand himself over", G1 news site reported.

And Workers’ Party Senator Lindbergh Farias called for activists to stand by the embattled leader on Friday. "Moro ordered prison for Lula. Everyone to Sao Bernardo tomorrow from 5am in front of Lula’s house!" he tweeted.

Moro’s order said that in view of Lula’s importance, a special cell "was prepared in advance... in which the ex-president will be separated from other prisoners, with no risk for his moral or physical integrity."

Lula was convicted last year of receiving a seaside apartment as a bribe from a construction company. A lower court appeal against the conviction was rejected this January.

On Wednesday, Lula petitioned to the Supreme Court to be allowed to remain free while pursuing appeals in higher courts. But the Supreme Court judges ruled 6-5 in a marathon session that under the law, Lula must begin his sentence after having lost that first appeal. — AFP