Thousands turned out to the streets of Brazil for anti-corruption demonstrations

Four government ministers and several deputies have left office over corruption allegations since President Dilma Rousseff took office in January.

Dozens of government officials have also lost their jobs or been arrested, and several other ministers have been accused of corruption, though all deny wrongdoing.

Some of the protesters chanted slogans in support of President Rousseff, who has promised a zero-tolerance approach to graft. Others gathered outside government ministries and the Congress with buckets and mops in a symbolic gesture to wash away corruption.

The demonstration in Brasilia – dubbed the March Against Corruption – had no political party affiliation. Many of the protesters were students, who organised the demonstration using social networking websites.

The protest was backed by Brazil’s College of Lawyers, the Brazilian Press Association, and the National Bishops’ Conference.

“Corruption in our country is a pandemic which threatens the credibility of institutions and the entire democratic system,” said the three organisations in a joint statement.

Justice Minister Eduardo Cardoso also voiced support. “We all have a duty to combat corruption and the president supports this,” he said. “I think it is a legitimate demonstration and an opportunity for everyone to fulfil their role as citizens.”

President Rousseff’s chief of staff, Antonio Palocci, resigned in June after media reports questioned his rapid accumulation of wealth. Since then, the ministers of defence, agriculture and transport have also been forced out of office by corruption allegations – though like Mr Palocci, all deny wrongdoing.

President Rousseff has won widespread praise for her firm reaction to the successive corruption scandals. But her determination to clean up her administration had put severe strain on her governing coalition, which is made up of more than a dozen parties.

Some Brazilian political parties have traditionally given their support to the government in return for official jobs for their members and for money – either for personal gain or for party funding.