The Datafolha polling institute found that 33pc of respondents said Bolsonaro was doing a "great or good" job. That is technically tied with the 32pc in an April Datafolha poll.

Those who think Bolsonaro is doing a "bad or awful" job rose to 33pc from 30pc in the April poll.

The latest polls show Bolsonaro technically tied with former President Fernando Henrique Cardoso as the leader with the least support at this point in his first term.

Thirty-four percent of those asked by Datafolha in June 1995 thought Cardoso was doing "good or great."

The poll of 2,086 people across Brazil on July 4-5 has a margin of error of 2 percentage points.  Bolsonaro easily won last year's election over leftist rival Fernando Haddad, who stepped in to take the top place on the Workers Party ticket after a graft conviction prevented imprisoned former President Luiz Inacio Lula da Silva from running.

Datafolha polls last year showed Lula far more popular than Bolsonaro - even after he had been imprisoned.

Lula's conviction has come under scrutiny since the publication of leaked messages last month by news website The Intercept Brasil showed former federal judge and current Justice Minister Sergio Moro stepping over ethical, and possibly legal, lines by coaching the prosecution in Lula's trial.

Moro, who presided over the case and found Lula guilty, has alternatively argued that the leaked messages show no improper behavior to questioning their authenticity, is facing withering criticism.

On Monday, Moro's press office said he would take the week of July 15-19 off for "personal" reasons, and later added he was spending time with his family.

Moro's wife and children do not live with him in the capital. July is winter recess for schools in Brazil.

In August the Supreme Court is expected to weigh an appeal from Lula's legal team, demanding his release from jail.

Lula has been convicted in a second graft trial and faces at least eight more.