BRASILIA (AFP) - Brazil's embattled President Dilma Rousseff has named her predecessor and mentor Luiz Inacio Lula da Silva as her new chief of staff, her office said on Wednesday.

The move comes as the two leftists who have led Brazil for the past 13 years fight for their political survival: Rousseff is facing an impeachment drive, mass protests and a deep recession, while Lula faces charges in an explosive corruption scandal.

"Ex-president Luiz Inacio Lula da Silva will assume the post of chief minister of state for the Casa Civil," a post equivalent to the president's chief of staff, said a statement from the presidency.

Lula replaces Jaques Wagner, a former governor.

Rousseff held a second round of talks with Lula early on Wednesday on the prospect of joining her government, after meeting with him for four hours the day before.

Top Rousseff allies have said the president needs Lula's political prowess and popularity with their left-wing base to fight off impeachment and the potential splintering of her coalition.

Opponents, however, see the move as an attempt to protect Lula from arrest after he was charged in a massive corruption investigation centred on state oil company Petrobras.

Cabinet ministers can only be tried before the Supreme Court in Brazil.

Lula (2003-2011) led Brazil through an economic boom and stepped down as a hero to the left after rolling out social programs that helped lift tens of millions of people from poverty.

But he is a divisive figure five years after stepping down.

He faces charges of accepting a luxury apartment as a bribe from a company implicated in the Petrobras scandal, and prosecutors have indicated they are investigating whether he played a more central role in the multi-billion-dollar corruption scheme.