Brasilia, Mar 14 (IANS): Some 3.3 million people across Brazil marched through the streets to demonstrate against the government over corruption and the economic downturn.

The protestors marched in more than 200 cities on Sunday, carrying placards, banners and balloons reading "Dilma Out, PT Out" in reference to President Dilma Rousseff and the ruling Workers' Party, Xinhua news agency reported.

Uniformly dressed in yellow and green, the colours of Brazil's flag, the demonstrators demanded the resignation of the president and the arrest of former president Luiz Inacio Lula da Silva who has been charged with money laundering and for concealing assets.

Nearly 50,000 people gathered around the National Congress building in the capital Brasilia, chanting "Dilma Out".

The protestors expressed firm support for the graft probe into alleged corruption at state-controlled oil and gas giant Petrobras.

Last week, Sao Paulo state prosecutors requested the preventive arrest of Lula, but the judge in charge of the case has yet to approve or reject it.

The preventive arrest is an instrument used under Brazilian law when there is a risk that the accused in a process will try to flee, tamper with evidence or threaten witnesses.

Rousseff refused to quit and said: "No one has the right to demand the resignation of a legitimately elected president without providing proof that she has violated the Constitution."