More than a million people have poured onto the streets of Brazil to demand the removal of the country's president Dilma Rousseff.

Rousseff is struggling to hold on to power in the face of a massive corruption scandal and the worst recession in decades.

The leftist leader issued a plea to people via the Brazilian media on Saturday, in which she said: "I am appealing for there not to be violence.

"I think all people have a right to be on the streets. However, no one has a right to be violent - no one."

Protests were held in around 300 Brazilian cities, with Sao Paulo seeing 1.4m protesters and at least 20,000 people gathering early to march in the capital Brasilia. It was predicted five times that number could join the protest as it progressed.

In Rio de Janeiro, which hosts the Summer Olympics in August, the crowd took over a long section of Avenida Atlantica, running along the beachfront of Copacabana.

Marcelo Antunes, 66, was protesting in Rio, where the mood was described as calm but angry.

He said: "I think all Brazilians need to participate - we can't stand aside.

"All revolutions in history were pushed by the masses."

Rio resident Maria do Carmo, 73, said: "We need to get rid of Dilma, the Workers' Party, the whole lot.

"It's not their time anymore."

Rousseff faces impeachment in the country's Congress over allegations she manipulated government accounts to boost public spending during her election campaign in 2014.

Prosecutors have charged her predecessor and mentor, Luiz Inacio Lula da Silva, with money laundering and requested his arrest in a case linked to a massive corruption scandal at state oil company Petrobras, accusations he has denied.

Rousseff says there isn't "the slightest possibility" she will resign, although polls show that more than half of Brazilians want her impeached.

Meanwhile, she is running out of allies, with the PMDB party threatening to pull out of the country's fragile coalition government in 30 days.

(Sky News)