A Roman Catholic bishop in Brazil has warned that a series of corruption scandals is putting the country's democracy at jeopardy, as the Supreme Court commenced hearings on a bribery affair involving 40 government allies.

Brazilian President Luiz Inacio Lula da Silva has been haunted by a series of corruption scandals involving leading government figures over the past three years that fly in the face of pledges he made when he first come to power in 2003 when he said he would clean up the political system.

Earlier this year, the president's Energy Minister resigned over accusations that he took a kickback for government contracts and Senate leader Renan Calheiros, from the largest party in his coalition, faces similar charges, Reuters reports.

Bishop Geraldo Lyrio Rocha, head of the Brazilian Bishops Conference CNBB said: "Corruption and impunity are leading our people to distrust politics. They represent a weakening of democracy."

The Supreme Court is also deciding whether to put 40 people on trial, which includes leaders of Lula's governing Working Party. They have been accused of running an illegal fundraising scheme to finance party election campaigns and bribe legislators.

Bishop Rocha said, "If there are culprits, punish them. If public assets were stolen, give them back.

"The current situation puts at risk the institutions of this country."

President Lula defended himself by saying that it only appears as though his government is more corrupt because his government is doing a better job of investigating cases.