Brasília: Brazilian President Dilma Rousseff launched a late bid Thursday to escape an impeachment vote seeking a court injunction to halt the proceedings after key allies deserted her.

The 68-year-old leftist leader's grip on power was slipping in a political and economic crisis rocking Latin America's biggest country less than four months before it hosts the Olympics.

Rousseff had been scratching around for support in the lower house of congress which is scheduled to vote Sunday on whether to move forward with impeachment proceedings.

On Thursday she launched a fresh line of defense. Her government's top lawyer Jose Eduardo Cardozo filed for an injunction to halt the weekend's proceedings.

A special Supreme Court session was underway Thursday night to examine the request.

Rousseff is fighting to save her presidency over charges that she illegally manipulated government accounts to mask the effects of recession during her 2014 re-election and in 2015.

The government's appeal alleged procedural failings in the case against Rousseff saying it had violated her right to a defense.

"Evidence unrelated to the case has been included in the process such as matters related to President Dilma (Rousseff)'s previous term" Cardozo said in the filing.

He called the impeachment drive "a truly Kafkaesque process in which the accused is unable to know precisely what she is accused of or why."

Rousseff has vowed not to back down but repeated an offer to forge a political compromise with opponents if she survives the key vote on Sunday.

"The government will fight until the last minute of the second half... to foil this coup attempt" she said in an interview published by various media outlets.

- Impeachment votes -

Rousseff on Thursday held a meeting with ministers and some of the lawmakers still loyal to her a presidential source said shortly before Cardozo announced his appeal.

Several of the parties in Rousseff's coalition have jumped ship starting with the PMDB of her vice president Michel Temer.

Scores of lawmakers have turned against Rousseff saying they will vote for impeachment.

The number of lawmakers who could vote against her on Sunday has crept close to the two-thirds majority of 342 lawmakers needed to pass the impeachment motion up to the Senate.

If the Senate in turn votes to open an impeachment trial Rousseff would be suspended from office for six months. Temer would step into her place while the impeachment process runs its course.

Rousseff has branded Temer a traitor. She says he is the leader of a "coup" against her along with the speaker of the lower house Eduardo Cunha.

Lawmakers who have yet to declare their position were facing fierce lobbying including from Rousseff's top ally and predecessor as president Luiz Inacio Lula da Silva.

But he too faces pressure: the courts have suspended his appointment as Rousseff's chief of staff over a corruption case against him linked to a huge graft scandal at state oil company Petrobras.

The country meanwhile has sunk into its worst recession in decades.

Protesters for and against Rousseff have called for demonstrations this weekend in Brasilia. Security forces have put up fences to protect government buildings from possible disturbances.

The president of the International Olympic Committee's coordination commission said Wednesday that preparations for the Olympics in August are running on time despite the political crisis.

The IOC "is working really hard to make sure that the deadlines are respected" Nawal El Moutawakel told a news conference in Rio de Janeiro where the Games will run from August 5 to 21.

"We are waiting for Sunday to see how the situation develops."

AFP