Tens of thousands of Brazilians joined protests in cities across the country on Sunday to protest against a bill which could result in ex-President Jair Bolsonaro being granted amnesty.

Bolsonaro was found guilty of plotting a coup earlier this month and has been sentenced to 27 years in prison. He will remain under house arrest until his lawyers have exhausted all appeals.

But the ex-leader's allies in the Chamber of Deputies have fast-tracked a bill which could see Bolsonaro and his co-defendants spared jail.

The demonstrators also expressed their anger at the lower house's passing of a constitutional amendment which would make it harder to launch criminal proceedings against lawmakers.

Under the proposal, members of Congress would have to give their approval - in a secret ballot - before a lawmaker could be charged or arrested.

Critics have dubbed it the "Banditry Bill" but members of Congress who supported it said it was necessary to shield them from what they said was "judicial overreach".

The proposed constitutional amendment will now go to the Senate.

Sunday's protests had the backing of trade unions, social groups and left-wing political parties and drew tens of thousands of attendees in several major cities.

Many chanted "no amnesty" and held up placards calling Congress "shameless".

At the event in Rio de Janeiro, veteran singers Chico Buarque, Gilberto Gil and Caetano Veloso entertained the crowds.

The demonstrations also drew the support of President Luiz Inácio Lula da Silva, who wrote on X: "I stand with the Brazilian people. Today's demonstrations show that the population does not want impunity or amnesty."

President Lula has also said that he would veto the amnesty bill were it to be passed by the Senate.

The anti-amnesty protests came two weeks after supporters of ex-President Bolsonaro took to the streets to denounce the legal proceedings against him.

The rival marches are a sign of how divided Brazilians remain over the Bolsonaro trial.

A majority of Supreme Court justices found that Bolsonaro and his seven co-defendants had conspired to try to cling to power after he lost the election to Lula in 2022.

The court said that while their efforts to launch a coup had failed because of lack of support from top military leaders, it had culminated in the storming of Congress, the Supreme Court and the presidential palace on 8 January 2023 by thousands of Bolsonaro supporters.

Order was quickly restored and more than 1,500 people were arrested, with some received lengthy sentences.

Bolsonaro's Liberal Party has been advocating for an amnesty for them and for the ex-president ever since.

But those who gathered on Sunday at the protests shouted "prison for Bolsonaro" and many told local reporters that they were "fighting for Brazil's democracy".

A survey published by pollster Datafolha on 16 September suggested that 50% of respondents thought Bolsonaro should go to prison, while 43% of the 2,005 people polled said he should not be jailed.