Brazil’s embattled president, Dilma Rousseff, has resorted to the country’s supreme court in a last-ditch attempt to avert likely defeat in a criticalimpeachment vote in congress that could lead to her removal from office.

Rousseff’s attorney general, José Eduardo Cardozo, asked the top court for an injunction to suspend Sunday’s lower house vote until the full court can rule on what he called procedural irregularities in the impeachment process.

Rousseff, already struggling with Brazil’s worst economic crisis in decades and a historic corruption scandal, has lost support within her governing coalition. She faces the growing likelihood of defeat in the lower house vote, which would send her impeachment to the senate for trial on charges of breaking budget laws.

If the senate accepts her impeachment, Rousseff would be suspended and replaced by Vice-President Michel Temer as soon as early May pending a trial that could last six months.