Rio de Janeiro (AFP) - Brazil's ex-president Luiz Inacio Lula da Silva, a key player in the political storm engulfing Latin America's biggest country, said Saturday that he hopes the Supreme Court will approve his entry into the government by Thursday.

Current President Dilma Rousseff named Lula her chief of staff in a bid to stiffen her desperate campaign to avoid impeachment in Congress.

However, the appointment was temporarily blocked in the Supreme Court after an opposition outcry that Lula was scheming to gain ministerial immunity so that he could avoid arrest in a federal corruption probe.

The court is due to make a final ruling shortly.

"On Thursday I will take up my post as chief of staff, if the Supreme Court approves, so that I can help President Dilma," Lula told a rally in the north-eastern city of Fortaleza.

"We have to guarantee Dilma's ability to govern," he said in a speech, quoted by the website of his Workers' Party.

Lula's struggle to enter the government is one of the many subplots of a political upheaval paralyzing Brazil as it sinks into its worst recession in a generation.

The court's ruling will come just as the impeachment fight approaches a new peak.

Rousseff, accused of illegal government accounting practices, will wrap up her defense at a congresional impeachment commission on Monday. The commission will deliberate before issuing its recommendation on about April 11.

The full lower house of Congress will then vote within days whether or not to send the impeachment case for a trial in the Senate.

Rousseff is frantically trying to find enough votes to prevent the two-thirds majority required in the lower house to trigger a trial. That became harder last week when the main coalition partner to her Workers' Party switched to the opposition.

Lula, who is accused of money laundering in a case linked to a huge corruption probe centered on state oil company Petrobras, is a hero to Brazil's left and seen by some as the only politician capable of turning Rousseff's flailing presidency around.

However, he is also detested by many in the center and on the right, and his attempt to enter government has energized the pro-impeachment camp.

Addressing loyalists in Fortaleza, the region where the Workers' Party and Rousseff retain strongest support, Lula said he had "never seen such a climate of hate in the country as there is now."

"Those who love democracy, those who like politics, wish respect for the most basic thing -- that is respect for the popular vote which elected Dilma," he said.