An impeachment trial of Ecuador's President Guillermo Lasso is set to begin on Tuesday, the head of the South American country's opposition-controlled parliament said.

National Assembly leader Virgilio Saquicela called Sunday on the unicameral body's 137 members to convene after a majority last week voted to proceed with the trial.

The proceedings come after online newspaper La Posta published allegations in January of widespread graft in public companies involving Lasso's brother-in-law Danilo Carrera.

Opposition MPs have accused the conservative president of being aware of the alleged corruption, in which a drug trafficking-accused businessman close to Carrera has also been implicated.

Lasso has argued that the allegations date to before he became president in May 2021.

In March, the Constitutional Court authorized the unicameral National Assembly to hold impeachment proceedings against Lasso for alleged embezzlement.

Successfully removing the 67-year-old former banker Lasso would require agreement from two-thirds of the assembly, or 92 votes.

Another impeachment attempt in June last year failed to garner enough votes.