Brazil's President Dilma Rousseff fights for her political life

Brazilian President Dilma Rousseff is fighting for her political life in Congress, the courts and streets this week, but her path to survival has got ever narrower, analysts said on Monday.

Rousseff faces impeachment proceedings over alleged fiscal mismanagement, while the Supreme Electoral Court is considering possible campaign funding irregularities that could end up annulling her 2014 reelection.

Those threats had appeared to be receding in the last few weeks. Even Rousseff's dismal popularity ratings were creeping up.

But on Friday, what analyst Gabriel Petrus called "an atomic bomb" was thrown at her leftist Workers' Party with the brief detention of Rousseff's mentor and charismatic predecessor, Luiz Inacio Lula da Silva.

Lula, as he is universally known, is accused of taking bribes from companies involved in the gargantuan embezzlement and kickbacks scheme at state oil company Petrobras.

And the extraordinary scene of a powerful ex-president being taken away by police, backed up by officers in camouflage with rifles, brought all the simmering tensions to a boil.

Now, with the relative lull forgotten, both the opposition and pro-Rousseff camps are promising to take to the streets, while opposition parties in Congress are licking their lips over a revitalised impeachment push.

Petrus, at the Brasilia-based consultancy Barral M Jorge Associates, said both Lula and Rousseff have their backs up against the wall — and if necessary will go down swinging.

"The Workers' Party will play a winner-take-all strategy — everything or nothing," said Petrus, adding, "I think both sides are preparing for that battle."

The Workers' Party will try to show its muscle with a series of demonstrations announced in big cities, tomorrow, March 18 and March 31.

But analysts believe the turnout will be dwarfed by opposition rallies across the country on Sunday — and that huge crowds could push hesitant congressional deputies over the edge in backing the push to impeach Rousseff.

David Fleischer, a political science professor at the University of Brasilia, said that prosecutors are "closing the circle" around Lula, who denies having taken corrupt money and denounced the police operation against him on Friday as "a show."

"He's going to be in jail in a few weeks probably," Fleischer predicted.